[centos][build] centos_xen_repo to place Xen YumRepo for xen-devel
[centos][build] centos_xen_repo to place Xen YumRepo for xen-devel

rackerlabs/openstack-guest-agents-unix,joejulian/openstack-guest-agents-unix,joejulian/openstack-guest-agents-unix,joejulian/openstack-guest-agents-unix,rackerlabs/openstack-guest-agents-unix,rackerlabs/openstack-guest-agents-unix