diff --git a/vendor/github.com/jessevdk/go-flags/parser.go b/vendor/github.com/jessevdk/go-flags/parser.go
new file mode 100644
index 0000000..3fc3f7b
--- /dev/null
+++ b/vendor/github.com/jessevdk/go-flags/parser.go
@@ -0,0 +1,714 @@
+// Copyright 2012 Jesse van den Kieboom. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package flags
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path"
+	"reflect"
+	"sort"
+	"strings"
+	"unicode/utf8"
+)
+
+// A Parser provides command line option parsing. It can contain several
+// option groups each with their own set of options.
+type Parser struct {
+	// Embedded, see Command for more information
+	*Command
+
+	// A usage string to be displayed in the help message.
+	Usage string
+
+	// Option flags changing the behavior of the parser.
+	Options Options
+
+	// NamespaceDelimiter separates group namespaces and option long names
+	NamespaceDelimiter string
+
+	// EnvNamespaceDelimiter separates group env namespaces and env keys
+	EnvNamespaceDelimiter string
+
+	// UnknownOptionsHandler is a function which gets called when the parser
+	// encounters an unknown option. The function receives the unknown option
+	// name, a SplitArgument which specifies its value if set with an argument
+	// separator, and the remaining command line arguments.
+	// It should return a new list of remaining arguments to continue parsing,
+	// or an error to indicate a parse failure.
+	UnknownOptionHandler func(option string, arg SplitArgument, args []string) ([]string, error)
+
+	// CompletionHandler is a function gets called to handle the completion of
+	// items. By default, the items are printed and the application is exited.
+	// You can override this default behavior by specifying a custom CompletionHandler.
+	CompletionHandler func(items []Completion)
+
+	// CommandHandler is a function that gets called to handle execution of a
+	// command. By default, the command will simply be executed. This can be
+	// overridden to perform certain actions (such as applying global flags)
+	// just before the command is executed. Note that if you override the
+	// handler it is your responsibility to call the command.Execute function.
+	//
+	// The command passed into CommandHandler may be nil in case there is no
+	// command to be executed when parsing has finished.
+	CommandHandler func(command Commander, args []string) error
+
+	internalError error
+}
+
+// SplitArgument represents the argument value of an option that was passed using
+// an argument separator.
+type SplitArgument interface {
+	// String returns the option's value as a string, and a boolean indicating
+	// if the option was present.
+	Value() (string, bool)
+}
+
+type strArgument struct {
+	value *string
+}
+
+func (s strArgument) Value() (string, bool) {
+	if s.value == nil {
+		return "", false
+	}
+
+	return *s.value, true
+}
+
+// Options provides parser options that change the behavior of the option
+// parser.
+type Options uint
+
+const (
+	// None indicates no options.
+	None Options = 0
+
+	// HelpFlag adds a default Help Options group to the parser containing
+	// -h and --help options. When either -h or --help is specified on the
+	// command line, the parser will return the special error of type
+	// ErrHelp. When PrintErrors is also specified, then the help message
+	// will also be automatically printed to os.Stdout.
+	HelpFlag = 1 << iota
+
+	// PassDoubleDash passes all arguments after a double dash, --, as
+	// remaining command line arguments (i.e. they will not be parsed for
+	// flags).
+	PassDoubleDash
+
+	// IgnoreUnknown ignores any unknown options and passes them as
+	// remaining command line arguments instead of generating an error.
+	IgnoreUnknown
+
+	// PrintErrors prints any errors which occurred during parsing to
+	// os.Stderr. In the special case of ErrHelp, the message will be printed
+	// to os.Stdout.
+	PrintErrors
+
+	// PassAfterNonOption passes all arguments after the first non option
+	// as remaining command line arguments. This is equivalent to strict
+	// POSIX processing.
+	PassAfterNonOption
+
+	// Default is a convenient default set of options which should cover
+	// most of the uses of the flags package.
+	Default = HelpFlag | PrintErrors | PassDoubleDash
+)
+
+type parseState struct {
+	arg        string
+	args       []string
+	retargs    []string
+	positional []*Arg
+	err        error
+
+	command *Command
+	lookup  lookup
+}
+
+// Parse is a convenience function to parse command line options with default
+// settings. The provided data is a pointer to a struct representing the
+// default option group (named "Application Options"). For more control, use
+// flags.NewParser.
+func Parse(data interface{}) ([]string, error) {
+	return NewParser(data, Default).Parse()
+}
+
+// ParseArgs is a convenience function to parse command line options with default
+// settings. The provided data is a pointer to a struct representing the
+// default option group (named "Application Options"). The args argument is
+// the list of command line arguments to parse. If you just want to parse the
+// default program command line arguments (i.e. os.Args), then use flags.Parse
+// instead. For more control, use flags.NewParser.
+func ParseArgs(data interface{}, args []string) ([]string, error) {
+	return NewParser(data, Default).ParseArgs(args)
+}
+
+// NewParser creates a new parser. It uses os.Args[0] as the application
+// name and then calls Parser.NewNamedParser (see Parser.NewNamedParser for
+// more details). The provided data is a pointer to a struct representing the
+// default option group (named "Application Options"), or nil if the default
+// group should not be added. The options parameter specifies a set of options
+// for the parser.
+func NewParser(data interface{}, options Options) *Parser {
+	p := NewNamedParser(path.Base(os.Args[0]), options)
+
+	if data != nil {
+		g, err := p.AddGroup("Application Options", "", data)
+
+		if err == nil {
+			g.parent = p
+		}
+
+		p.internalError = err
+	}
+
+	return p
+}
+
+// NewNamedParser creates a new parser. The appname is used to display the
+// executable name in the built-in help message. Option groups and commands can
+// be added to this parser by using AddGroup and AddCommand.
+func NewNamedParser(appname string, options Options) *Parser {
+	p := &Parser{
+		Command:               newCommand(appname, "", "", nil),
+		Options:               options,
+		NamespaceDelimiter:    ".",
+		EnvNamespaceDelimiter: "_",
+	}
+
+	p.Command.parent = p
+
+	return p
+}
+
+// Parse parses the command line arguments from os.Args using Parser.ParseArgs.
+// For more detailed information see ParseArgs.
+func (p *Parser) Parse() ([]string, error) {
+	return p.ParseArgs(os.Args[1:])
+}
+
+// ParseArgs parses the command line arguments according to the option groups that
+// were added to the parser. On successful parsing of the arguments, the
+// remaining, non-option, arguments (if any) are returned. The returned error
+// indicates a parsing error and can be used with PrintError to display
+// contextual information on where the error occurred exactly.
+//
+// When the common help group has been added (AddHelp) and either -h or --help
+// was specified in the command line arguments, a help message will be
+// automatically printed if the PrintErrors option is enabled.
+// Furthermore, the special error type ErrHelp is returned.
+// It is up to the caller to exit the program if so desired.
+func (p *Parser) ParseArgs(args []string) ([]string, error) {
+	if p.internalError != nil {
+		return nil, p.internalError
+	}
+
+	p.eachOption(func(c *Command, g *Group, option *Option) {
+		option.clearReferenceBeforeSet = true
+		option.updateDefaultLiteral()
+	})
+
+	// Add built-in help group to all commands if necessary
+	if (p.Options & HelpFlag) != None {
+		p.addHelpGroups(p.showBuiltinHelp)
+	}
+
+	compval := os.Getenv("GO_FLAGS_COMPLETION")
+
+	if len(compval) != 0 {
+		comp := &completion{parser: p}
+		items := comp.complete(args)
+
+		if p.CompletionHandler != nil {
+			p.CompletionHandler(items)
+		} else {
+			comp.print(items, compval == "verbose")
+			os.Exit(0)
+		}
+
+		return nil, nil
+	}
+
+	s := &parseState{
+		args:    args,
+		retargs: make([]string, 0, len(args)),
+	}
+
+	p.fillParseState(s)
+
+	for !s.eof() {
+		var err error
+		arg := s.pop()
+
+		// When PassDoubleDash is set and we encounter a --, then
+		// simply append all the rest as arguments and break out
+		if (p.Options&PassDoubleDash) != None && arg == "--" {
+			s.addArgs(s.args...)
+			break
+		}
+
+		if !argumentIsOption(arg) {
+			if (p.Options&PassAfterNonOption) != None && s.lookup.commands[arg] == nil {
+				// If PassAfterNonOption is set then all remaining arguments
+				// are considered positional
+				if err = s.addArgs(s.arg); err != nil {
+					break
+				}
+
+				if err = s.addArgs(s.args...); err != nil {
+					break
+				}
+
+				break
+			}
+
+			// Note: this also sets s.err, so we can just check for
+			// nil here and use s.err later
+			if p.parseNonOption(s) != nil {
+				break
+			}
+
+			continue
+		}
+
+		prefix, optname, islong := stripOptionPrefix(arg)
+		optname, _, argument := splitOption(prefix, optname, islong)
+
+		if islong {
+			err = p.parseLong(s, optname, argument)
+		} else {
+			err = p.parseShort(s, optname, argument)
+		}
+
+		if err != nil {
+			ignoreUnknown := (p.Options & IgnoreUnknown) != None
+			parseErr := wrapError(err)
+
+			if parseErr.Type != ErrUnknownFlag || (!ignoreUnknown && p.UnknownOptionHandler == nil) {
+				s.err = parseErr
+				break
+			}
+
+			if ignoreUnknown {
+				s.addArgs(arg)
+			} else if p.UnknownOptionHandler != nil {
+				modifiedArgs, err := p.UnknownOptionHandler(optname, strArgument{argument}, s.args)
+
+				if err != nil {
+					s.err = err
+					break
+				}
+
+				s.args = modifiedArgs
+			}
+		}
+	}
+
+	if s.err == nil {
+		p.eachOption(func(c *Command, g *Group, option *Option) {
+			err := option.clearDefault()
+			if err != nil {
+				if _, ok := err.(*Error); !ok {
+					err = p.marshalError(option, err)
+				}
+				s.err = err
+			}
+		})
+
+		s.checkRequired(p)
+	}
+
+	var reterr error
+
+	if s.err != nil {
+		reterr = s.err
+	} else if len(s.command.commands) != 0 && !s.command.SubcommandsOptional {
+		reterr = s.estimateCommand()
+	} else if cmd, ok := s.command.data.(Commander); ok {
+		if p.CommandHandler != nil {
+			reterr = p.CommandHandler(cmd, s.retargs)
+		} else {
+			reterr = cmd.Execute(s.retargs)
+		}
+	} else if p.CommandHandler != nil {
+		reterr = p.CommandHandler(nil, s.retargs)
+	}
+
+	if reterr != nil {
+		var retargs []string
+
+		if ourErr, ok := reterr.(*Error); !ok || ourErr.Type != ErrHelp {
+			retargs = append([]string{s.arg}, s.args...)
+		} else {
+			retargs = s.args
+		}
+
+		return retargs, p.printError(reterr)
+	}
+
+	return s.retargs, nil
+}
+
+func (p *parseState) eof() bool {
+	return len(p.args) == 0
+}
+
+func (p *parseState) pop() string {
+	if p.eof() {
+		return ""
+	}
+
+	p.arg = p.args[0]
+	p.args = p.args[1:]
+
+	return p.arg
+}
+
+func (p *parseState) peek() string {
+	if p.eof() {
+		return ""
+	}
+
+	return p.args[0]
+}
+
+func (p *parseState) checkRequired(parser *Parser) error {
+	c := parser.Command
+
+	var required []*Option
+
+	for c != nil {
+		c.eachGroup(func(g *Group) {
+			for _, option := range g.options {
+				if !option.isSet && option.Required {
+					required = append(required, option)
+				}
+			}
+		})
+
+		c = c.Active
+	}
+
+	if len(required) == 0 {
+		if len(p.positional) > 0 {
+			var reqnames []string
+
+			for _, arg := range p.positional {
+				argRequired := (!arg.isRemaining() && p.command.ArgsRequired) || arg.Required != -1 || arg.RequiredMaximum != -1
+
+				if !argRequired {
+					continue
+				}
+
+				if arg.isRemaining() {
+					if arg.value.Len() < arg.Required {
+						var arguments string
+
+						if arg.Required > 1 {
+							arguments = "arguments, but got only " + fmt.Sprintf("%d", arg.value.Len())
+						} else {
+							arguments = "argument"
+						}
+
+						reqnames = append(reqnames, "`"+arg.Name+" (at least "+fmt.Sprintf("%d", arg.Required)+" "+arguments+")`")
+					} else if arg.RequiredMaximum != -1 && arg.value.Len() > arg.RequiredMaximum {
+						if arg.RequiredMaximum == 0 {
+							reqnames = append(reqnames, "`"+arg.Name+" (zero arguments)`")
+						} else {
+							var arguments string
+
+							if arg.RequiredMaximum > 1 {
+								arguments = "arguments, but got " + fmt.Sprintf("%d", arg.value.Len())
+							} else {
+								arguments = "argument"
+							}
+
+							reqnames = append(reqnames, "`"+arg.Name+" (at most "+fmt.Sprintf("%d", arg.RequiredMaximum)+" "+arguments+")`")
+						}
+					}
+				} else {
+					reqnames = append(reqnames, "`"+arg.Name+"`")
+				}
+			}
+
+			if len(reqnames) == 0 {
+				return nil
+			}
+
+			var msg string
+
+			if len(reqnames) == 1 {
+				msg = fmt.Sprintf("the required argument %s was not provided", reqnames[0])
+			} else {
+				msg = fmt.Sprintf("the required arguments %s and %s were not provided",
+					strings.Join(reqnames[:len(reqnames)-1], ", "), reqnames[len(reqnames)-1])
+			}
+
+			p.err = newError(ErrRequired, msg)
+			return p.err
+		}
+
+		return nil
+	}
+
+	names := make([]string, 0, len(required))
+
+	for _, k := range required {
+		names = append(names, "`"+k.String()+"'")
+	}
+
+	sort.Strings(names)
+
+	var msg string
+
+	if len(names) == 1 {
+		msg = fmt.Sprintf("the required flag %s was not specified", names[0])
+	} else {
+		msg = fmt.Sprintf("the required flags %s and %s were not specified",
+			strings.Join(names[:len(names)-1], ", "), names[len(names)-1])
+	}
+
+	p.err = newError(ErrRequired, msg)
+	return p.err
+}
+
+func (p *parseState) estimateCommand() error {
+	commands := p.command.sortedVisibleCommands()
+	cmdnames := make([]string, len(commands))
+
+	for i, v := range commands {
+		cmdnames[i] = v.Name
+	}
+
+	var msg string
+	var errtype ErrorType
+
+	if len(p.retargs) != 0 {
+		c, l := closestChoice(p.retargs[0], cmdnames)
+		msg = fmt.Sprintf("Unknown command `%s'", p.retargs[0])
+		errtype = ErrUnknownCommand
+
+		if float32(l)/float32(len(c)) < 0.5 {
+			msg = fmt.Sprintf("%s, did you mean `%s'?", msg, c)
+		} else if len(cmdnames) == 1 {
+			msg = fmt.Sprintf("%s. You should use the %s command",
+				msg,
+				cmdnames[0])
+		} else if len(cmdnames) > 1 {
+			msg = fmt.Sprintf("%s. Please specify one command of: %s or %s",
+				msg,
+				strings.Join(cmdnames[:len(cmdnames)-1], ", "),
+				cmdnames[len(cmdnames)-1])
+		}
+	} else {
+		errtype = ErrCommandRequired
+
+		if len(cmdnames) == 1 {
+			msg = fmt.Sprintf("Please specify the %s command", cmdnames[0])
+		} else if len(cmdnames) > 1 {
+			msg = fmt.Sprintf("Please specify one command of: %s or %s",
+				strings.Join(cmdnames[:len(cmdnames)-1], ", "),
+				cmdnames[len(cmdnames)-1])
+		}
+	}
+
+	return newError(errtype, msg)
+}
+
+func (p *Parser) parseOption(s *parseState, name string, option *Option, canarg bool, argument *string) (err error) {
+	if !option.canArgument() {
+		if argument != nil {
+			return newErrorf(ErrNoArgumentForBool, "bool flag `%s' cannot have an argument", option)
+		}
+
+		err = option.set(nil)
+	} else if argument != nil || (canarg && !s.eof()) {
+		var arg string
+
+		if argument != nil {
+			arg = *argument
+		} else {
+			arg = s.pop()
+
+			if validationErr := option.isValidValue(arg); validationErr != nil {
+				return newErrorf(ErrExpectedArgument, validationErr.Error())
+			} else if p.Options&PassDoubleDash != 0 && arg == "--" {
+				return newErrorf(ErrExpectedArgument, "expected argument for flag `%s', but got double dash `--'", option)
+			}
+		}
+
+		if option.tag.Get("unquote") != "false" {
+			arg, err = unquoteIfPossible(arg)
+		}
+
+		if err == nil {
+			err = option.set(&arg)
+		}
+	} else if option.OptionalArgument {
+		option.empty()
+
+		for _, v := range option.OptionalValue {
+			err = option.set(&v)
+
+			if err != nil {
+				break
+			}
+		}
+	} else {
+		err = newErrorf(ErrExpectedArgument, "expected argument for flag `%s'", option)
+	}
+
+	if err != nil {
+		if _, ok := err.(*Error); !ok {
+			err = p.marshalError(option, err)
+		}
+	}
+
+	return err
+}
+
+func (p *Parser) marshalError(option *Option, err error) *Error {
+	s := "invalid argument for flag `%s'"
+
+	expected := p.expectedType(option)
+
+	if expected != "" {
+		s = s + " (expected " + expected + ")"
+	}
+
+	return newErrorf(ErrMarshal, s+": %s",
+		option,
+		err.Error())
+}
+
+func (p *Parser) expectedType(option *Option) string {
+	valueType := option.value.Type()
+
+	if valueType.Kind() == reflect.Func {
+		return ""
+	}
+
+	return valueType.String()
+}
+
+func (p *Parser) parseLong(s *parseState, name string, argument *string) error {
+	if option := s.lookup.longNames[name]; option != nil {
+		// Only long options that are required can consume an argument
+		// from the argument list
+		canarg := !option.OptionalArgument
+
+		return p.parseOption(s, name, option, canarg, argument)
+	}
+
+	return newErrorf(ErrUnknownFlag, "unknown flag `%s'", name)
+}
+
+func (p *Parser) splitShortConcatArg(s *parseState, optname string) (string, *string) {
+	c, n := utf8.DecodeRuneInString(optname)
+
+	if n == len(optname) {
+		return optname, nil
+	}
+
+	first := string(c)
+
+	if option := s.lookup.shortNames[first]; option != nil && option.canArgument() {
+		arg := optname[n:]
+		return first, &arg
+	}
+
+	return optname, nil
+}
+
+func (p *Parser) parseShort(s *parseState, optname string, argument *string) error {
+	if argument == nil {
+		optname, argument = p.splitShortConcatArg(s, optname)
+	}
+
+	for i, c := range optname {
+		shortname := string(c)
+
+		if option := s.lookup.shortNames[shortname]; option != nil {
+			// Only the last short argument can consume an argument from
+			// the arguments list, and only if it's non optional
+			canarg := (i+utf8.RuneLen(c) == len(optname)) && !option.OptionalArgument
+
+			if err := p.parseOption(s, shortname, option, canarg, argument); err != nil {
+				return err
+			}
+		} else {
+			return newErrorf(ErrUnknownFlag, "unknown flag `%s'", shortname)
+		}
+
+		// Only the first option can have a concatted argument, so just
+		// clear argument here
+		argument = nil
+	}
+
+	return nil
+}
+
+func (p *parseState) addArgs(args ...string) error {
+	for len(p.positional) > 0 && len(args) > 0 {
+		arg := p.positional[0]
+
+		if err := convert(args[0], arg.value, arg.tag); err != nil {
+			p.err = err
+			return err
+		}
+
+		if !arg.isRemaining() {
+			p.positional = p.positional[1:]
+		}
+
+		args = args[1:]
+	}
+
+	p.retargs = append(p.retargs, args...)
+	return nil
+}
+
+func (p *Parser) parseNonOption(s *parseState) error {
+	if len(s.positional) > 0 {
+		return s.addArgs(s.arg)
+	}
+
+	if len(s.command.commands) > 0 && len(s.retargs) == 0 {
+		if cmd := s.lookup.commands[s.arg]; cmd != nil {
+			s.command.Active = cmd
+			cmd.fillParseState(s)
+
+			return nil
+		} else if !s.command.SubcommandsOptional {
+			s.addArgs(s.arg)
+			return newErrorf(ErrUnknownCommand, "Unknown command `%s'", s.arg)
+		}
+	}
+
+	return s.addArgs(s.arg)
+}
+
+func (p *Parser) showBuiltinHelp() error {
+	var b bytes.Buffer
+
+	p.WriteHelp(&b)
+	return newError(ErrHelp, b.String())
+}
+
+func (p *Parser) printError(err error) error {
+	if err != nil && (p.Options&PrintErrors) != None {
+		flagsErr, ok := err.(*Error)
+
+		if ok && flagsErr.Type == ErrHelp {
+			fmt.Fprintln(os.Stdout, err)
+		} else {
+			fmt.Fprintln(os.Stderr, err)
+		}
+	}
+
+	return err
+}