Move unittest tests underneath it in /pkg

pkg/unittest/tests/unittest_test.dart

 // Copyright (c) 2012, 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.
 
 // TODO(gram):
 // Unfortunately I can't seem to test anything that involves timeouts, e.g.
 // insufficient callbacks, because the timeout is controlled externally
 // (test.dart?), and we would need to use a shorter timeout for the inner tests
 // so the outer timeout doesn't fire. So I removed all such tests.
 // I'd like to revisit this at some point.
@@ skipping 178 matching lines @@
     buildStatusString(1, 0, 0, tests[9], 10),
     buildStatusString(0, 1, 0, tests[10], message: 'Caught error!'),
     buildStatusString(1, 0, 1, 'testOne', message: 'Callback called after already being marked as done (1).:testTwo:')
   ];
 
   actual = [];
 
   nextTest(0);
 }