add a mdss group to the CLI testing inventory
add a mdss group to the CLI testing inventory

The ceph-mds role is being tested, but there was not group for it in the
inventory so ceph-mds was not being installed on the testing machine.

Signed-off-by: Andrew Schoen <1bb641dc23c3a93cce4eee683bcf4b2bea7903a3@redhat.com>

fgal/ceph-ansible,jtaleric/ceph-ansible,albertomurillo/ceph-ansible,fgal/ceph-ansible,jsaintrocc/ceph-ansible,travmi/ceph-ansible,WingkaiHo/ceph-ansible,jfcoz/ceph-ansible,font/ceph-ansible,WingkaiHo/ceph-ansible,WingkaiHo/ceph-ansible,jsaintrocc/ceph-ansible,jtaleric/ceph-ansible,verdurin/ceph-ansible-1,guits/ceph-ansible,albertomurillo/ceph-ansible,albertomurillo/ceph-ansible,bengland2/ceph-ansible,bengland2/ceph-ansible,travmi/ceph-ansible,verdurin/ceph-ansible-1,jfcoz/ceph-ansible,ceph/ceph-ansible,mcsage/ceph-ansible,font/ceph-ansible,ceph/ceph-ansible,guits/ceph-ansible,mcsage/ceph-ansible