Get rid of all the library tags.

test/serve/web_socket/url_to_asset_id_errors_test.dart

 // Copyright (c) 2014, 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 file.
 
-library pub_tests;
-
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 import '../utils.dart';
 
 main() {
   setUp(() {
     d.dir(appPath, [
       d.appPubspec()
@@ skipping 10 matching lines @@
   });
 
   integration("responds with NOT_SERVED for an unknown port", () {
     pubServe();
     expectWebSocketError("urlToAssetId", {
       "url": "http://localhost:80/index.html"
     }, NOT_SERVED, '"localhost:80" is not being served by pub.');
     endPubServe();
   });
 }