Get rid of all the library tags.

test/transformer/exclusion/include_asset_prefix_test.dart

Index: test/transformer/exclusion/include_asset_prefix_test.dart
diff --git a/test/transformer/exclusion/include_asset_prefix_test.dart b/test/transformer/exclusion/include_asset_prefix_test.dart
index fa761a460000bb1298d6c097b38c171aaf49bf36..ebb56180b61a4c272e8f7613b0478a369a0907d0 100644
--- a/test/transformer/exclusion/include_asset_prefix_test.dart
+++ b/test/transformer/exclusion/include_asset_prefix_test.dart
@@ -2,8 +2,6 @@
 // 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 '../../serve/utils.dart';