[VOL-4291] Rw-core updates for gRPC migration

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/github.com/coreos/etcd/pkg/httputil/httputil.go b/vendor/github.com/coreos/etcd/pkg/httputil/httputil.go
new file mode 100644
index 0000000..09f44e7
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/pkg/httputil/httputil.go
@@ -0,0 +1,22 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// borrowed from golang/net/context/ctxhttp/cancelreq.go
+
+// Package httputil provides HTTP utility functions.
+package httputil
+
+import (
+	"io"
+	"io/ioutil"
+	"net/http"
+)
+
+// GracefulClose drains http.Response.Body until it hits EOF
+// and closes it. This prevents TCP/TLS connections from closing,
+// therefore available for reuse.
+func GracefulClose(resp *http.Response) {
+	io.Copy(ioutil.Discard, resp.Body)
+	resp.Body.Close()
+}