bringup tests

*Added dependency cob_safety_controller 
*Removes arg <machine..> https://github.com/ros-drivers/openni2_launch/commit/bbcf9f5451c2536736537e4d35bb1d1175065090

There already is a ```cob_safety_controller``` package in ```cob_substitute``` (since hydro)
see [here](https://github.com/ipa320/cob_substitute/tree/hydro_dev/cob_safety_controller)