Get rid of all the library tags.

test/serve/gets_first_if_git_url_changed_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 '../descriptor.dart' as d;
 import '../test_pub.dart';
 import 'utils.dart';
 
 main() {
   integration("gets first if a git dependency's url doesn't match the one in "
       "the lock file", () {
     d.git("foo-before.git", [
       d.libPubspec("foo", "1.0.0"),
       d.libDir("foo", "before")
@@ skipping 14 matching lines @@
     d.appDir({
       "foo": {"git": "../foo-after.git"}
     }).create();
 
     pubGet();
     pubServe();
     requestShouldSucceed("packages/foo/foo.dart", 'main() => "after";');
     endPubServe();
   });
 }