vendor: update google gensupport

vendor/google.golang.org/api/gensupport/header.go

@@ -0,0 +1,22 @@
+// Copyright 2017 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.
+
+package gensupport
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+)
+
+// GoogleClientHeader returns the value to use for the x-goog-api-client
+// header, which is used internally by Google.
+func GoogleClientHeader(generatorVersion, clientElement string) string {
+	elts := []string{"gl-go/" + strings.Replace(runtime.Version(), " ", "_", -1)}
+	if clientElement != "" {
+		elts = append(elts, clientElement)
+	}
+	elts = append(elts, fmt.Sprintf("gdcl/%s", generatorVersion))
+	return strings.Join(elts, " ")
+}

vendor/vendor.json

@@ -3255,10 +3255,10 @@
 			"revisionTime": "2016-11-27T23:54:21Z"
 		},
 		{
-			"checksumSHA1": "a1NkriuA/uk+Wv6yCFzxz4LIaDg=",
+			"checksumSHA1": "C7k1pbU/WU4CBoBwA4EBUnV/iek=",
 			"path": "google.golang.org/api/gensupport",
-			"revision": "8840436417f044055c16fc7e4018f08484f52839",
-			"revisionTime": "2017-01-13T00:03:17Z"
+			"revision": "bc20c61134e1d25265dd60049f5735381e79b631",
+			"revisionTime": "2017-02-10T21:56:36Z"
 		},
 		{
 			"checksumSHA1": "yQREK/OWrz9PLljbr127+xFk6J0=",