A new validation check:

* validate_count_as_odd_for_role
  As the name describes we want to check that we have an odd number
  of nodes used in a role.

Signed-off-by: JuanJose 'JJ' Galvez <jj.galvez@inktank.com>
Merge pull request #963 from jgalvez/pull-req-release-roxy-master-5458bf315d94064341d4731918096a43df5e57ae

Check for odd number of ceph-mon in proposal [1/2]