Don't include roboclaw.py ourselves

[Achllle]

Instead of duplicating the source for the roboclaw code (roboclaw.py), we should clone the official repo, perhaps fork it to turn it into a catkin or pip package.

This ensure we can get updates properly, keep our codebase smaller and cleaner, and report issues related to roboclaw code in their repo where we will find official support.

[Achllle]

Or, since the official repo isn't the greatest of quality and has zero documentation or support, it might make sense to turn to user repos:

• https://github.com/csvance/roboclaw c++, intended support for this repo
• https://github.com/sonyccd/roboclaw_ros not maintained, seems for diff drives only
• https://github.com/urill/pyroboclaw less attractive

[Achllle]

I'm working on this at https://github.com/Achllle/libroboclaw and https://github.com/Achllle/roboclaw-hardware-interface

[ericjunkins]

roger 👍