Gemify Ruby Library

Introduces this repo as a Ruby gem. This adds some really nice stuff, such as testing, versioning, depedencies, etc. All of which will drastically ease its use in other projects.

This also updates the library for the new API version. The documentation changes will follow.

I'm explicitly keeping the oAuth tokens hidden for now. Until we either hear word of an official program for getting them, or Tesla OK's the use of the ones from the app (very unlikely), I'll keep them that way. I really don't want to be rude to Tesla and force them to issue a C&D. This API is a privilege, not a right. Play nicely :smile: