update gazebo tags for sensor plugins
deleted unnecessary head versions
Merge pull request #104 from ipa-fxm/hydro_dev

update gazebo tags for sensor plugins
Merge pull request #108 from ipa-nhg/head

deleted unnecessary head versions
no inertia in base_footprint
Merge pull request #109 from ipa-fxm/hydro_dev

no inertia in base_footprint