Switch to using the dep tool and update all the dependencies

vendor/cloud.google.com/go/internal/version/update_version.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+today=$(date +%Y%m%d)
+
+sed -i -r -e 's/const Repo = "([0-9]{8})"/const Repo = "'$today'"/' $GOFILE
+

vendor/cloud.google.com/go/internal/version/version.go

@@ -0,0 +1,49 @@
+// 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.
+
+//go:generate ./update_version.sh
+
+// Package version contains version information for Google Cloud Client
+// Libraries for Go, as reported in request headers.
+package version
+
+import (
+	"bytes"
+	"runtime"
+	"unicode"
+)
+
+// Repo is the current version of the client libraries in this
+// repo. It should be a date in YYYYMMDD format.
+const Repo = "20170210"
+
+// Go returns the Go runtime version. The returned string
+// has no whitespace.
+func Go() string {
+	return goVersion
+}
+
+var goVersion = removeWhitespace(runtime.Version())
+
+func removeWhitespace(s string) string {
+	var buf bytes.Buffer
+	for _, r := range s {
+		if unicode.IsSpace(r) {
+			buf.WriteByte('_')
+		} else {
+			buf.WriteRune(r)
+		}
+	}
+	return buf.String()
+}

vendor/cloud.google.com/go/internal/version/version_test.go

@@ -0,0 +1,47 @@
+// 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 version
+
+import (
+	"regexp"
+	"testing"
+)
+
+func TestGo(t *testing.T) {
+	got := Go()
+	want := `^\S+$`
+	match, err := regexp.MatchString(want, got)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !match {
+		t.Errorf("got %q, want match of regexp %q", got, want)
+	}
+}
+
+func TestRemoveWhitespace(t *testing.T) {
+	for _, test := range []struct {
+		in, want string
+	}{
+		{"", ""},
+		{"go1.7", "go1.7"},
+		{" a b c ", "_a_b_c_"},
+		{"a\tb\t c\n", "a_b__c_"},
+	} {
+		if got := removeWhitespace(test.in); got != test.want {
+			t.Errorf("removeWhitespace(%q) = %q, want %q", test.in, got, test.want)
+		}
+	}
+}