WIP - Adding tutum support

This is a WIP PR for adding tutum support to fog.

Tutum is a docker container PAAS providing three main models, containers, images and applications. An application consists of N containers based off of the same image. 

Still todo

* Add requests and tests
* Get all tests working
I'm thinking the best way would be to allow the user to specify version as a fog parameter, pass that down to the request level as an option and the model level as an attr_accessor, and isolate it to the lowest level. As long as new fields are added/removed to maintain compatibility changes it should be ok.