Fix for ROS dep. of ROS overlays

Fix for ROS dependencies of ROS overlays.  ROS dependencies must be installed in
the virtual Python enviroment created by Robustus under every condition that
this script is call (was failing with system ROS).
Refinements to "rosdep" fix

Refinements to "rosdep" fix.
PEP8

PEP8.
Merge pull request #74 from braincorp/kulungowski_robustus

Kulungowski robustus