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
Ah, interesting. Not presently. Some APIs have `servers.all(some-kind-of-filter)` type invocations, think that might be the closest. We hadn't really had a case come up with getting multiple by key before, perhaps we should consider creating a pattern to follow here.