do a full gyro calibration

def cmd_gyrocal(self, args):
        '''do a full gyro calibration'''
        mav = self.master
        mav.mav.command_long_send(mav.target_system, mav.target_component,
                                  mavutil.mavlink.MAV_CMD_PREFLIGHT_CALIBRATION, 0,
                                  1, 0, 0, 0, 0, 0, 0)