HOT template to deploy chef server

Added a HOT template to deploy a server using Open Source CHEF.
The template uses the CHEF OmniTruck API to retrieve the latest
stable release of Open Source Chef Server. This is a single resource
template and is compatible with Ubuntu as well as CentOS/RHEL.

Change-Id: I407f0666fa269044ba7d07caa9a0dab59ffdb936