first pass at adding havana repo for centOS/RHEL

Currently, the cookbooks attempt to install centOS/RHEL packages from
epel, since no other repo is configured.  epel contains folsom packages.

This commit drops in the official havana repo/gpg key so at least the
correct set of packages will attempt to be installed by chef.

Implements: blueprint centos-rhel-for-common

Change-Id: I76edc6538a71a8fb5f4242e8174aff9b3831834f
Merge "first pass at adding havana repo for centOS/RHEL"