beta: Small scap fixes

* Require ::role::labs::lvm::srv instead of using labs_lvm::volume
  directly.
* Add system::role descriptions for role::beta::rsync_slave and
  role::beta::scap_target.
* Fix filename in FIXME for role::beta::rsync_slave.
* Add role::beta::jobrunner to bundle scap and jobrunner settings.

Change-Id: Ica12bcf42c4dd3d18a42780a3be7b3d24ae764e7
Merge "beta: Small scap fixes" into production