Chef version update, Ubuntu Update, Python Dependency change

Howdy!

* Removed the version constraint for `python`.  The existing `Berksfile` cites a non-community cookbook, so the constraint causes dependency resolutions with berkshelf 3 for sure.  Since the `Berksfile` locks python to that repo and commit, the cookbook still works properly.
* Set Vagrant to use Ubuntu 13.10 (Verified it's working)
* Updated version of chef to use (11.12.4, the latest)

Didn't try on 14.04 yet since many cookbooks don't have full support yet.