Use the new test runner.

test/dependency_override_test.dart

 // Copyright (c) 2013, 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.
 
 import 'package:path/path.dart' as path;
 
 import 'descriptor.dart' as d;
 import 'test_pub.dart';
 
 main() {
-  initConfig();
   forBothPubGetAndUpgrade((command) {
     integration("chooses best version matching override constraint", () {
       servePackages((builder) {
         builder.serve("foo", "1.0.0");
         builder.serve("foo", "2.0.0");
         builder.serve("foo", "3.0.0");
       });
 
       d.dir(appPath, [
         d.pubspec({
@@ skipping 92 matching lines @@
       schedulePub(args: [command.name], output: command.success, error:
           """
           Warning: You are using these overridden dependencies:
           ! bar 1.0.0
           ! baz 0.0.1 from path $bazPath
           ! foo 1.0.0
           """);
     });
   });
 }