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/go.etcd.io/etcd/clientv3/retry_interceptor.go b/vendor/go.etcd.io/etcd/clientv3/retry_interceptor.go
index 6b1054e..e48a003 100644
--- a/vendor/go.etcd.io/etcd/clientv3/retry_interceptor.go
+++ b/vendor/go.etcd.io/etcd/clientv3/retry_interceptor.go
@@ -48,7 +48,7 @@
 			if err := waitRetryBackoff(ctx, attempt, callOpts); err != nil {
 				return err
 			}
-			logger.Info(
+			logger.Debug(
 				"retrying of unary invoker",
 				zap.String("target", cc.Target()),
 				zap.Uint("attempt", attempt),
@@ -112,7 +112,7 @@
 			return nil, grpc.Errorf(codes.Unimplemented, "clientv3/retry_interceptor: cannot retry on ClientStreams, set Disable()")
 		}
 		newStreamer, err := streamer(ctx, desc, cc, method, grpcOpts...)
-		logger.Info("retry stream intercept", zap.Error(err))
+		logger.Warn("retry stream intercept", zap.Error(err))
 		if err != nil {
 			// TODO(mwitkow): Maybe dial and transport errors should be retriable?
 			return nil, err
@@ -228,7 +228,7 @@
 	if s.callOpts.retryAuth && rpctypes.Error(err) == rpctypes.ErrInvalidAuthToken {
 		gterr := s.client.getToken(s.ctx)
 		if gterr != nil {
-			s.client.lg.Info("retry failed to fetch new auth token", zap.Error(gterr))
+			s.client.lg.Warn("retry failed to fetch new auth token", zap.Error(gterr))
 			return false, err // return the original error for simplicity
 		}
 		return true, err