Upgrade to test 0.12.0.

test/command_runner_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS 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 command_runner_test;
 
 import 'package:args/command_runner.dart';
-import 'package:unittest/unittest.dart';
+import 'package:test/test.dart';
 
 import 'utils.dart';
 
 const _DEFAULT_USAGE = """
 Usage: test <command> [arguments]
 
 Global options:
 -h, --help    Print this usage information.
 
 Available commands:
@@ skipping 261 matching lines @@
 
       expect(runner.run(["foo", "bar"]), throwsUsageError(
           'Command "foo" does not take any arguments.', """
 Usage: test foo [arguments]
 -h, --help    Print this usage information.
 
 Run "test help" to see global options."""));
     });
   });
 }