Fix test failures for source recipe, add EL7 support.

This fixes #41 as well as adds support for Ubuntu 10.04 and EL7.
Use string interpolation for binary download URL.
Remove spec_helper.rb from root of project.

This seems to have slipped through a little bit.
Add chef-provisioning recipe for easy bootstrapping.
Fix the EL6 version which runs in test-kitchen.
Make chef-provisioning cookbook a weak dependency.

This is only suggested if you want to use chef-provisioning to start a
cluster using the recipe in the root of the directory.
Fix UI recipe to use string interpolation for base url.
Fix test to revert back to using proper golang version.
Tag a stab at 0.5.2 changelog?
Make the tests go green.
Merge pull request #88 from johnbellone/develop

WIP: LISA conference hacking