Use "package:" imports for pub.

test/lish/archives_and_uploads_a_package_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 'dart:convert';
 
+import 'package:pub/src/exit_codes.dart' as exit_codes;
 import 'package:scheduled_test/scheduled_test.dart';
 import 'package:scheduled_test/scheduled_server.dart';
 import 'package:shelf/shelf.dart' as shelf;
 
-import '../../lib/src/exit_codes.dart' as exit_codes;
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import 'utils.dart';
 
 main() {
   initConfig();
   setUp(d.validPackage.create);
 
   integration('archives and uploads a package', () {
     var server = new ScheduledServer();
@@ skipping 11 matching lines @@
     });
 
     pub.stdout.expect(startsWith('Uploading...'));
     pub.stdout.expect('Package test_pkg 1.0.0 uploaded!');
     pub.shouldExit(exit_codes.SUCCESS);
   });
 
   // TODO(nweiz): Once a multipart/form-data parser in Dart exists, we should
   // test that "pub lish" chooses the correct files to publish.
 }