`stop_action` is not used, instead it is hardcoded

[tylerfowle]

https://github.com/antonvh/mpy-robot-tools/blob/b3ab8c92a3644dcee7e8e0d9584a4099c1b3195a/mpy_robot_tools/ctrl_plus.py#L129
https://github.com/antonvh/mpy-robot-tools/blob/b3ab8c92a3644dcee7e8e0d9584a4099c1b3195a/mpy_robot_tools/ctrl_plus.py#L149
https://github.com/antonvh/mpy-robot-tools/blob/b3ab8c92a3644dcee7e8e0d9584a4099c1b3195a/mpy_robot_tools/ctrl_plus.py#L154