minor change
Merge branch 'master' of https://github.com/selfsame/mars_base.git
Merge branch 'master' of https://github.com/selfsame/mars_base.git
Merge branch 'master' of https://github.com/selfsame/mars_base.git
Merge branch 'master' of https://github.com/selfsame/mars_base.git
Merge branch 'master' of https://github.com/selfsame/mars_base.git
Merge branch 'master' of https://github.com/selfsame/mars_base.git
adding craters, working on map