Make integration tests a bit cleaner.

utils/tests/pub/update/git/update_to_nonexistent_pubspec_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 '../../test_pub.dart';
-import '../../../../../pkg/unittest/lib/unittest.dart';
 
 main() {
-  test("updates Git packages to a nonexistent pubspec", () {
+  integration("updates Git packages to a nonexistent pubspec", () {
     ensureGit();
 
     var repo = git('foo.git', [
       libDir('foo'),
       libPubspec('foo', '1.0.0')
     ]);
     repo.scheduleCreate();
 
     appDir([{"git": "../foo.git"}]).scheduleCreate();
 
@@ skipping 12 matching lines @@
     schedulePub(args: ['update'],
         error: new RegExp(r'Package "foo" doesn' "'" r't have a '
             r'pubspec.yaml file.'),
         exitCode: 1);
 
     dir(packagesPath, [
       dir('foo', [
         file('foo.dart', 'main() => "foo";')
       ])
     ]).scheduleValidate();
-
-    run();
   });
 }