Merge pull request #37 from ipa-fxm/hydro_dev

bring groovy updates to hydro + make it work
change dependency from gazebo to gazebo_ros
Merge pull request #38 from mas-group/hydro_dev

change dependency from gazebo to gazebo_ros
Merge branch 'hydro_dev' of github.com:ipa320/cob_simulation into hydro_dev