Get rid of all the library tags.

test/serve/serve_from_dependency_lib_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("'packages' URLs look in the dependency's lib directory", () {
     d.dir("foo", [
       d.libPubspec("foo", "0.0.1"),
       d.dir("lib", [
         d.file("lib.dart", "foo() => 'foo';"),
@@ skipping 13 matching lines @@
     pubServe();
     requestShouldSucceed("packages/foo/lib.dart", "foo() => 'foo';");
     requestShouldSucceed("packages/foo/sub/lib.dart", "bar() => 'bar';");
 
     // "packages" can be in a subpath of the URL:
     requestShouldSucceed("foo/packages/foo/lib.dart", "foo() => 'foo';");
     requestShouldSucceed("a/b/packages/foo/sub/lib.dart", "bar() => 'bar';");
     endPubServe();
   });
 }