Add Berkshelf, RuboCop, Test Kitchen, etc.

* Config to test Ubuntu 12.04 & Debian 7.2
* RuboCop config to set code style expectations
* Minimal Berksfile
* Rakefile with handy test tasks
Add ChefSpec tests, use bleeding-edge ark

Need the bleeding edge ark so we have access to the ChefSpec matchers
that haven't landed in a released version yet.

Courtesy of that unreleased ark, some breaking changes to the LWRP:

* Add ark prefix_home to deal w/ ark changes
Add Travis CI style & unit testing
Add ServerSpec tests