SEBA-902 single-olt tests;
Pin protoc-gen-go to 1.3.2 to resolve compatibility issue;
Run go mod tidy / go mod vendor on importer;
Add Go Module support to demotest

Change-Id: Ifde824fc9a6317b0adc1e12bea54ee1f9b788906
diff --git a/vendor/google.golang.org/grpc/vet.sh b/vendor/google.golang.org/grpc/vet.sh
index 0e73707..f077fe7 100644
--- a/vendor/google.golang.org/grpc/vet.sh
+++ b/vendor/google.golang.org/grpc/vet.sh
@@ -94,7 +94,7 @@
 gofmt -s -d -l . 2>&1 | fail_on_output
 goimports -l . 2>&1 | (! grep -vE "(_mock|\.pb)\.go")
 golint ./... 2>&1 | (! grep -vE "(_mock|\.pb)\.go:")
-go vet -all .
+go vet -all ./...
 
 misspell -error .
 
@@ -151,6 +151,7 @@
 grpc.WithServiceConfig
 grpc.WithTimeout
 http.CloseNotifier
+info.SecurityVersion
 naming.Resolver
 naming.Update
 naming.Watcher