add obstacle avoiding straight line testing
Merge remote-tracking branch 'origin/josias'
Merge remote-tracking branch 'origin/master'
add obstacle avoiding test
Merge branch 'master' of https://github.com/turly221/Explore.git
test commit for feifan branch
Merge remote-tracking branch 'origin/feifan'
Latest copy manually merged with Feifan's
Merge branch 'master' of local repository into josias