catkin_tools build system for Atom

Uses the atom-build package to execute catkin build for the catkin_tools package.

• Assuming the open project is either a catkin_tools workspace or a ROS package, this executes the catkin build command.
• Notice that as for now the catkin_tools workspace must have been built once.

Thanks to build-cmake from which this package is largely inspired.

** Note This package requires atom-build to be installed.

TODO :

• [x] enable options.
• [x] choosing ROS_VERSION to be sourced.
• [x] passing args to catkin build.
• [x] option to clean first.
• [ ] allows for custom source path.
• [ ] support for catkin_make.