Merge pull request #1 from vinayyadav3016/master

First basic simulation envionment added.
Merge pull request #3 from vinayyadav3016/master

Added msg stack
added package simulator_auv_model in simulator stack
added simulator model package
Merge branch 'master' of https://github.com/prudhvid/kraken_3.0

merging
Merge pull request #4 from prudhvid/master

Added simulator_physics_model
Added Comments and fixed roll bug