enable grpc retry

Change-Id: Id9f1cd18324e2788b2e6c4a9838ffff80ee49f0f
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/retry/doc.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/retry/doc.go
new file mode 100644
index 0000000..afd924a
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/retry/doc.go
@@ -0,0 +1,25 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+/*
+`grpc_retry` provides client-side request retry logic for gRPC.
+
+Client-Side Request Retry Interceptor
+
+It allows for automatic retry, inside the generated gRPC code of requests based on the gRPC status
+of the reply. It supports unary (1:1), and server stream (1:n) requests.
+
+By default the interceptors *are disabled*, preventing accidental use of retries. You can easily
+override the number of retries (setting them to more than 0) with a `grpc.ClientOption`, e.g.:
+
+ myclient.Ping(ctx, goodPing, grpc_retry.WithMax(5))
+
+Other default options are: retry on `ResourceExhausted` and `Unavailable` gRPC codes, use a 50ms
+linear backoff with 10% jitter.
+
+For chained interceptors, the retry interceptor will call every interceptor that follows it
+whenever when a retry happens.
+
+Please see examples for more advanced use.
+*/
+package grpc_retry