Sp18021 feat ros coding style

[tylerlum]

Issue: Format and coding style of stage_ros was not up to modern standards.

Solution:

1. Reformat code to follow ROS C++ Code Style Guidelines (eg. 2 spaces indent, curly brackets on their own line, etc.)
2. Migrate package.xml file to format 2
3. Add roslint to package, then edit code to meet all roslint and catkin lint standards