Add generated file

This PR adds generated files under pkg/client and vendor folder.

vendor/golang.org/x/tools/cmd/getgo/server/README.md

@@ -0,0 +1,7 @@
+# getgo server
+
+## Deployment
+
+```
+gcloud app deploy --promote --project golang-org
+```

vendor/golang.org/x/tools/cmd/getgo/server/app.yaml

@@ -0,0 +1,7 @@
+runtime: go
+service: get
+api_version: go1
+
+handlers:
+- url: /.*
+  script: _go_app

vendor/golang.org/x/tools/cmd/getgo/server/main.go

@@ -0,0 +1,61 @@
+// 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.
+
+// Command server serves get.golang.org, redirecting users to the appropriate
+// getgo installer based on the request path.
+package server
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+)
+
+const (
+	base             = "https://dl.google.com/go/getgo/"
+	windowsInstaller = base + "installer.exe"
+	linuxInstaller   = base + "installer_linux"
+	macInstaller     = base + "installer_darwin"
+)
+
+// substring-based redirects.
+var stringMatch = map[string]string{
+	// via uname, from bash
+	"MINGW":  windowsInstaller, // Reported as MINGW64_NT-10.0 in git bash
+	"Linux":  linuxInstaller,
+	"Darwin": macInstaller,
+}
+
+func init() {
+	http.HandleFunc("/", handler)
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	if containsIgnoreCase(r.URL.Path, "installer.exe") {
+		// cache bust
+		http.Redirect(w, r, windowsInstaller+cacheBust(), http.StatusFound)
+		return
+	}
+
+	for match, redirect := range stringMatch {
+		if containsIgnoreCase(r.URL.Path, match) {
+			http.Redirect(w, r, redirect, http.StatusFound)
+			return
+		}
+	}
+
+	http.NotFound(w, r)
+}
+
+func containsIgnoreCase(s, substr string) bool {
+	return strings.Contains(
+		strings.ToLower(s),
+		strings.ToLower(substr),
+	)
+}
+
+func cacheBust() string {
+	return fmt.Sprintf("?%d", time.Now().Nanosecond())
+}