Get rid of all the library tags.

test/version_solver_test.dart

Index: test/version_solver_test.dart
diff --git a/test/version_solver_test.dart b/test/version_solver_test.dart
index 23e853ee9fcb55fa4330fdfc8eb5187e28cdad87..5fba6da5e52f51d46dadaff04630aad4b44686e1 100644
--- a/test/version_solver_test.dart
+++ b/test/version_solver_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_upgrade_test;
-
 import 'dart:async';
 
 import 'package:pub/src/lock_file.dart';