repo: support custom apt repos

Signed-off-by: Alexandre Marangone <alexandre.marangone@inktank.com>
Roles: Add ceph::repo recipe

Fixes: https://github.com/ceph/ceph-cookbooks/pull/30

Signed-off-by: Alexandre Marangone <alexandre.marangone@inktank.com>
Repo: support custom rpm repos

Signed-off-by: Alexandre Marangone <alexandre.marangone@inktank.com>
Merge pull request #31 from ceph/wip-repo

Wip repo