Use the new test runner.

test/packages_file_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS d.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 d.file.
 
 import 'descriptor.dart' as d;
 import 'test_pub.dart';
 
 main() {
-  initConfig();
   forBothPubGetAndUpgrade((command) {
     integration('.packages file is created', () {
       servePackages((builder) {
         builder.serve("foo", "1.2.3",
             deps: {'baz': '2.2.2'}, contents: [d.dir("lib", [])]);
         builder.serve("bar", "3.2.1", contents: [d.dir("lib", [])]);
         builder.serve("baz", "2.2.2",
             deps: {"bar": "3.2.1"}, contents: [d.dir("lib", [])]);
       });
 
@@ skipping 61 matching lines @@
       ]).create();
 
       pubCommand(command);
 
       d.dir(appPath, [d.packagesFile({"myapp": "0.0.0",
                                       "baz": "../local_baz"})]).validate();
     });
 
   });
 }