'Test that we can rename a file.'

def testRename(self):

    def _check(results):
        self.assertEqual(results[0], '')
        self.assertEqual(results[1], 'testfile2')
        return self.runCommand('rename    testfile2    testfile1')
    d = self.runScript('rename    testfile1    testfile2', 'ls    testfile?')
    d.addCallback(_check)
    d.addCallback(self.assertEqual, '')
    return d
