'``CAScript.main`` returns a ``Deferred`` on success.'

def test_deferred_result(self):

    path = FilePath(self.mktemp())
    path.makedirs()
    cwd = os.getcwd()
    self.addCleanup(os.chdir, cwd)
    os.chdir(path.path)
    options = CAOptions()
    options.parseOptions(['initialize', 'mycluster'])
    script = CAScript()
    dummy_reactor = object()
    self.assertEqual(None, self.successResultOf(script.main(dummy_reactor, options)))
