* manifests/site.pp
* modules/openstack_project/manifests/git_backend.pp: Add the zuul
server's public SSH key to a dedicated zuul account on the git
server farm. This will allow zuul to push arbitrary references into
its scratch repositories. Also set ownership on its scratch
repository hierarchy and pack them, properly skipping it in the
existing cgit repo repack since ownership differs.
Change-Id: I4b5b583847c828aadc903270433882531e5b1ea7
73c0175819