diff --git a/vendor/github.com/kelseyhightower/envconfig/envconfig.go b/vendor/github.com/kelseyhightower/envconfig/envconfig.go
new file mode 100644
index 0000000..3ad5e7d
--- /dev/null
+++ b/vendor/github.com/kelseyhightower/envconfig/envconfig.go
@@ -0,0 +1,298 @@
+// Copyright (c) 2013 Kelsey Hightower. All rights reserved.
+// Use of this source code is governed by the MIT License that can be found in
+// the LICENSE file.
+
+package envconfig
+
+import (
+	"encoding"
+	"errors"
+	"fmt"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// ErrInvalidSpecification indicates that a specification is of the wrong type.
+var ErrInvalidSpecification = errors.New("specification must be a struct pointer")
+
+// A ParseError occurs when an environment variable cannot be converted to
+// the type required by a struct field during assignment.
+type ParseError struct {
+	KeyName   string
+	FieldName string
+	TypeName  string
+	Value     string
+	Err       error
+}
+
+// Decoder has the same semantics as Setter, but takes higher precedence.
+// It is provided for historical compatibility.
+type Decoder interface {
+	Decode(value string) error
+}
+
+// Setter is implemented by types can self-deserialize values.
+// Any type that implements flag.Value also implements Setter.
+type Setter interface {
+	Set(value string) error
+}
+
+func (e *ParseError) Error() string {
+	return fmt.Sprintf("envconfig.Process: assigning %[1]s to %[2]s: converting '%[3]s' to type %[4]s. details: %[5]s", e.KeyName, e.FieldName, e.Value, e.TypeName, e.Err)
+}
+
+// varInfo maintains information about the configuration variable
+type varInfo struct {
+	Name  string
+	Alt   string
+	Key   string
+	Field reflect.Value
+	Tags  reflect.StructTag
+}
+
+// GatherInfo gathers information about the specified struct
+func gatherInfo(prefix string, spec interface{}) ([]varInfo, error) {
+	expr := regexp.MustCompile("([^A-Z]+|[A-Z][^A-Z]+|[A-Z]+)")
+	s := reflect.ValueOf(spec)
+
+	if s.Kind() != reflect.Ptr {
+		return nil, ErrInvalidSpecification
+	}
+	s = s.Elem()
+	if s.Kind() != reflect.Struct {
+		return nil, ErrInvalidSpecification
+	}
+	typeOfSpec := s.Type()
+
+	// over allocate an info array, we will extend if needed later
+	infos := make([]varInfo, 0, s.NumField())
+	for i := 0; i < s.NumField(); i++ {
+		f := s.Field(i)
+		ftype := typeOfSpec.Field(i)
+		if !f.CanSet() || ftype.Tag.Get("ignored") == "true" {
+			continue
+		}
+
+		for f.Kind() == reflect.Ptr {
+			if f.IsNil() {
+				if f.Type().Elem().Kind() != reflect.Struct {
+					// nil pointer to a non-struct: leave it alone
+					break
+				}
+				// nil pointer to struct: create a zero instance
+				f.Set(reflect.New(f.Type().Elem()))
+			}
+			f = f.Elem()
+		}
+
+		// Capture information about the config variable
+		info := varInfo{
+			Name:  ftype.Name,
+			Field: f,
+			Tags:  ftype.Tag,
+			Alt:   strings.ToUpper(ftype.Tag.Get("envconfig")),
+		}
+
+		// Default to the field name as the env var name (will be upcased)
+		info.Key = info.Name
+
+		// Best effort to un-pick camel casing as separate words
+		if ftype.Tag.Get("split_words") == "true" {
+			words := expr.FindAllStringSubmatch(ftype.Name, -1)
+			if len(words) > 0 {
+				var name []string
+				for _, words := range words {
+					name = append(name, words[0])
+				}
+
+				info.Key = strings.Join(name, "_")
+			}
+		}
+		if info.Alt != "" {
+			info.Key = info.Alt
+		}
+		if prefix != "" {
+			info.Key = fmt.Sprintf("%s_%s", prefix, info.Key)
+		}
+		info.Key = strings.ToUpper(info.Key)
+		infos = append(infos, info)
+
+		if f.Kind() == reflect.Struct {
+			// honor Decode if present
+			if decoderFrom(f) == nil && setterFrom(f) == nil && textUnmarshaler(f) == nil {
+				innerPrefix := prefix
+				if !ftype.Anonymous {
+					innerPrefix = info.Key
+				}
+
+				embeddedPtr := f.Addr().Interface()
+				embeddedInfos, err := gatherInfo(innerPrefix, embeddedPtr)
+				if err != nil {
+					return nil, err
+				}
+				infos = append(infos[:len(infos)-1], embeddedInfos...)
+
+				continue
+			}
+		}
+	}
+	return infos, nil
+}
+
+// Process populates the specified struct based on environment variables
+func Process(prefix string, spec interface{}) error {
+	infos, err := gatherInfo(prefix, spec)
+
+	for _, info := range infos {
+
+		// `os.Getenv` cannot differentiate between an explicitly set empty value
+		// and an unset value. `os.LookupEnv` is preferred to `syscall.Getenv`,
+		// but it is only available in go1.5 or newer. We're using Go build tags
+		// here to use os.LookupEnv for >=go1.5
+		value, ok := lookupEnv(info.Key)
+		if !ok && info.Alt != "" {
+			value, ok = lookupEnv(info.Alt)
+		}
+
+		def := info.Tags.Get("default")
+		if def != "" && !ok {
+			value = def
+		}
+
+		req := info.Tags.Get("required")
+		if !ok && def == "" {
+			if req == "true" {
+				return fmt.Errorf("required key %s missing value", info.Key)
+			}
+			continue
+		}
+
+		err := processField(value, info.Field)
+		if err != nil {
+			return &ParseError{
+				KeyName:   info.Key,
+				FieldName: info.Name,
+				TypeName:  info.Field.Type().String(),
+				Value:     value,
+				Err:       err,
+			}
+		}
+	}
+
+	return err
+}
+
+// MustProcess is the same as Process but panics if an error occurs
+func MustProcess(prefix string, spec interface{}) {
+	if err := Process(prefix, spec); err != nil {
+		panic(err)
+	}
+}
+
+func processField(value string, field reflect.Value) error {
+	typ := field.Type()
+
+	decoder := decoderFrom(field)
+	if decoder != nil {
+		return decoder.Decode(value)
+	}
+	// look for Set method if Decode not defined
+	setter := setterFrom(field)
+	if setter != nil {
+		return setter.Set(value)
+	}
+
+	if t := textUnmarshaler(field); t != nil {
+		return t.UnmarshalText([]byte(value))
+	}
+
+	if typ.Kind() == reflect.Ptr {
+		typ = typ.Elem()
+		if field.IsNil() {
+			field.Set(reflect.New(typ))
+		}
+		field = field.Elem()
+	}
+
+	switch typ.Kind() {
+	case reflect.String:
+		field.SetString(value)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		var (
+			val int64
+			err error
+		)
+		if field.Kind() == reflect.Int64 && typ.PkgPath() == "time" && typ.Name() == "Duration" {
+			var d time.Duration
+			d, err = time.ParseDuration(value)
+			val = int64(d)
+		} else {
+			val, err = strconv.ParseInt(value, 0, typ.Bits())
+		}
+		if err != nil {
+			return err
+		}
+
+		field.SetInt(val)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		val, err := strconv.ParseUint(value, 0, typ.Bits())
+		if err != nil {
+			return err
+		}
+		field.SetUint(val)
+	case reflect.Bool:
+		val, err := strconv.ParseBool(value)
+		if err != nil {
+			return err
+		}
+		field.SetBool(val)
+	case reflect.Float32, reflect.Float64:
+		val, err := strconv.ParseFloat(value, typ.Bits())
+		if err != nil {
+			return err
+		}
+		field.SetFloat(val)
+	case reflect.Slice:
+		vals := strings.Split(value, ",")
+		sl := reflect.MakeSlice(typ, len(vals), len(vals))
+		for i, val := range vals {
+			err := processField(val, sl.Index(i))
+			if err != nil {
+				return err
+			}
+		}
+		field.Set(sl)
+	}
+
+	return nil
+}
+
+func interfaceFrom(field reflect.Value, fn func(interface{}, *bool)) {
+	// it may be impossible for a struct field to fail this check
+	if !field.CanInterface() {
+		return
+	}
+	var ok bool
+	fn(field.Interface(), &ok)
+	if !ok && field.CanAddr() {
+		fn(field.Addr().Interface(), &ok)
+	}
+}
+
+func decoderFrom(field reflect.Value) (d Decoder) {
+	interfaceFrom(field, func(v interface{}, ok *bool) { d, *ok = v.(Decoder) })
+	return d
+}
+
+func setterFrom(field reflect.Value) (s Setter) {
+	interfaceFrom(field, func(v interface{}, ok *bool) { s, *ok = v.(Setter) })
+	return s
+}
+
+func textUnmarshaler(field reflect.Value) (t encoding.TextUnmarshaler) {
+	interfaceFrom(field, func(v interface{}, ok *bool) { t, *ok = v.(encoding.TextUnmarshaler) })
+	return t
+}