Get rid of all the library tags.

test/snapshot/prints_errors_for_broken_snapshots_test.dart

Index: test/snapshot/prints_errors_for_broken_snapshots_test.dart
diff --git a/test/snapshot/prints_errors_for_broken_snapshots_test.dart b/test/snapshot/prints_errors_for_broken_snapshots_test.dart
index 61721345d14fdc328570f23ae63cd6078bba7c3a..25a814a2ebacedef5eb28271264aa51f2db34b48 100644
--- a/test/snapshot/prints_errors_for_broken_snapshots_test.dart
+++ b/test/snapshot/prints_errors_for_broken_snapshots_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 'package:path/path.dart' as p;
 import 'package:scheduled_test/scheduled_test.dart';