bringup tests

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

we need to be careful here because cob_safety_controller is in a private repo.
so either we need to have an entry in cob_substitute or make the cob_safety_controller public. I vote for having it in cob_substitute.