Clean up after each case.

        Stop harness service, close browser and close DUT.

def tearDown(self):
        """Clean up after each case.

        Stop harness service, close browser and close DUT.
        """
        if self.__class__ is HarnessCase:
            return

        logger.info('Tearing down')
        self._destroy_harness()
        self._destroy_browser()
        self._destroy_dut()
        self._destroy_rf_shield()