BZ #1050182 - remove the Gluster Storage Host Group.

https://bugzilla.redhat.com/show_bug.cgi?id=1050182

Remove the Gluster Storage Host Group -- Foreman is not responsible
for managing gluster back ends.
Merge pull request #99 from cwolferh/bz1050182_rm_gluster_storage_host_group

BZ #1050182 - remove the Gluster Storage Host Group.