'Test if command fails with command topic.'

def test_fail_setup_if_no_command_topic(self):

    with assert_setup_component(0, light.DOMAIN):
        assert setup_component(self.hass, light.DOMAIN, {light.DOMAIN: {'platform': 'mqtt', 'name': 'test'}})
    self.assertIsNone(self.hass.states.get('light.test'))
