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
For now I'll manually get and populate an array.

What do you think of overriding the containers attribute, or do I need to maintain that attribute for parsing? Should I preserve the raw field and use an alias for the object array?