Import puppet-yum project

Adds a new yum module which can be used to manage individual
yum::repo's with puppet. This approach uses reposync
and createrepo to provide a lightweight HTTP based local
Yum repo syncing mechanism. The resulting directories
are hosted in /srv/yum_repos/ via Apache.
This will be useful for TripleO where we heavily leverage
Fedora Yum repos for disk image building.

Tested on a Centos 6.5 host machine.

Change-Id: Ice268e404df7c7608a5cb733ea65050e705ff2ab
Merge "Import puppet-yum project"