Switch to using the dep tool and update all the dependencies

vendor/cloud.google.com/go/compute/metadata/metadata.go

@@ -17,7 +17,7 @@
 //
 // This package is a wrapper around the GCE metadata service,
 // as documented at https://developers.google.com/compute/docs/metadata.
-package metadata
+package metadata // import "cloud.google.com/go/compute/metadata"
 
 import (
 	"encoding/json"

vendor/cloud.google.com/go/compute/metadata/metadata_test.go

@@ -0,0 +1,48 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metadata
+
+import (
+	"os"
+	"sync"
+	"testing"
+)
+
+func TestOnGCE_Stress(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping in -short mode")
+	}
+	var last bool
+	for i := 0; i < 100; i++ {
+		onGCEOnce = sync.Once{}
+
+		now := OnGCE()
+		if i > 0 && now != last {
+			t.Errorf("%d. changed from %v to %v", i, last, now)
+		}
+		last = now
+	}
+	t.Logf("OnGCE() = %v", last)
+}
+
+func TestOnGCE_Force(t *testing.T) {
+	onGCEOnce = sync.Once{}
+	old := os.Getenv(metadataHostEnv)
+	defer os.Setenv(metadataHostEnv, old)
+	os.Setenv(metadataHostEnv, "127.0.0.1")
+	if !OnGCE() {
+		t.Error("OnGCE() = false; want true")
+	}
+}