VOL-1460 Updated core to use voltha-protos instead of local protos
Moved protos to python directory in order to maintain functionaly of containers built there.
Added capability to do local builds of protos
Added instructions on running dep ensure for getting protos.
Updated github.com/golang/protobuf version to v1.3.1

Change-Id: Ia6ef55f07f0d5dcb5b750d7c37b21b71db85bfc4
diff --git a/vendor/google.golang.org/grpc/call.go b/vendor/google.golang.org/grpc/call.go
index 100f05d..9e20e4d 100644
--- a/vendor/google.golang.org/grpc/call.go
+++ b/vendor/google.golang.org/grpc/call.go
@@ -40,7 +40,7 @@
 func combine(o1 []CallOption, o2 []CallOption) []CallOption {
 	// we don't use append because o1 could have extra capacity whose
 	// elements would be overwritten, which could cause inadvertent
-	// sharing (and race connditions) between concurrent calls
+	// sharing (and race conditions) between concurrent calls
 	if len(o1) == 0 {
 		return o2
 	} else if len(o2) == 0 {