Adding a Collins inventory script for Ansible

Ansible is swiftly becoming one of the most exciting projects in DevOps, and the more that I've worked with it, the more that I've wanted to add inventorying support for a tool known as Collins, which was developed by Tumblr for managing large amounts of hardware assets.  It provides a UI and rich API for intaking and tracking hardware assets of all types, which makes it an ideal 'single point of truth' for inventorying the wide breadth of hardware devices manageable by Ansible.

This pull request adds support for using the Collins asset management database as a dynamic inventory source for Ansible actions.  It is based off mdehaan's Cobbler inventorying script, and creating Ansible host groupings based off the following Collins asset attributes:

 - All built-in and user-defined attributes
 - Asset state (e.g. Allocated, Maintenance, Incomplete, etc.)
 - Hardware type

Furthermore, all facts exposed by Collins are provided for each host for driving automation and templating purposes.

More information about Collins and its API can be found here:

 - http://tumblr.github.io/collins/
 - http://tumblr.github.io/collins/api.html

Thanks very much for looking this over; here is a picture of Phil Collins with some kittens for your consideration:

![](http://38.media.tumblr.com/dbd9bfafcc7e504c6084fb8eb986f856/tumblr_myciy2yYRE1sg3xpdo1_500.jpg)