Use "package:" imports for pub.

test/lish/force_publishes_if_there_are_warnings_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_server.dart';
 import 'package:scheduled_test/scheduled_stream.dart';
 import 'package:scheduled_test/scheduled_test.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('--force publishes if there are warnings', () {
     var pkg = packageMap("test_pkg", "1.0.0");
@@ skipping 15 matching lines @@
 
     pub.shouldExit(exit_codes.SUCCESS);
     pub.stderr.expect(consumeThrough('Suggestions:'));
     pub.stderr.expect(emitsLines(
         '* Author "Natalie Weizenbaum" in pubspec.yaml should have an email '
             'address\n'
         '  (e.g. "name <email>").'));
     pub.stdout.expect(consumeThrough('Package test_pkg 1.0.0 uploaded!'));
   });
 }