Support running on dev hardware and small clean up

I wanted to be able to test and develop on my desktop machine without having to ssh into the raspberry pi to test changes. Added a mocked GPIO class that's imported when the RPi.GPIO library isn't available (non-raspberry PI machines). It's just a stub right now, but would be cool to have it print to console in the future to help with debugging and testing.
Added a GitIgnore to prevent development files from ending up in the repo
Noticed the resources were lower cased both because they won't ever be exported and also because BrewSettings and CoffeeInfo would collide with their respective models. Made everything uppercase, to clearly show resources as classes, and including all models behind their module namespace to prevent the collision.
Made the REST URIs for BrewSettings and CoffeeInfo adhere with the casing of their siblings.
Cleaned up models a bit. Exposed the methods as static and named the parameters for clarity.
Made helpers a python module and now including barcode.py functions as a namespace for clarity.

margyle / decaf