Move pub into sdk/lib/_internal.

utils/tests/pub/update/hosted/fail_gracefully_on_url_resolve_test.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library pub_tests;
-
-import 'dart:io';
-
-import '../../descriptor.dart' as d;
-import '../../test_pub.dart';
-
-main() {
-  initConfig();
-  integration('fails gracefully if the url does not resolve', () {
-    d.dir(appPath, [
-      d.pubspec({
-        "name": "myapp",
-        "dependencies": {
-          "foo": {
-            "hosted": {
-              "name": "foo",
-              "url": "http://pub.invalid"
-            }
-          }
-         }
-      })
-    ]).create();
-
-    schedulePub(args: ['update'],
-        error: new RegExp('Could not resolve URL "http://pub.invalid".'),
-        exitCode: 1);
-  });
-}