Get rid of all the library tags.

test/serve/native_watch_removed_file_test.dart

 // Copyright (c) 2013, 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:path/path.dart' as path;
 import 'package:pub/src/io.dart';
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import 'utils.dart';
 
 // TODO(nweiz): Default to testing the native watcher and add an explicit test
 // for the polling watcher when issue 14941 is fixed.
@@ skipping 13 matching lines @@
     requestShouldSucceed("index.html", "body");
 
     schedule(() => deleteEntry(
         path.join(sandboxDir, appPath, "web", "index.html")));
 
     waitForBuildSuccess();
     requestShould404("index.html");
     endPubServe();
   });
 }