Interface should expose colocation of services

[Chris MacNaughton]

It is currently required to spelunk into the interface's common.py code to enable colocation of services with code such as:

        import hooks.relations.hacluster.common as hacluster_common
        crm = hacluster_common.CRM()
        crm.colocation('ganesha_with_vip',
                       'inf',
                       'res_nfs_ganesha_nfs_ganesha',
                       'grp_ganesha_vips')

It would be great if the interface supported this

[Billy Olsen (billy-olsen)]

I believe this is resolved with https://opendev.org/openstack/charm-interface-hacluster/commit/fa48a2151f86c2e983a174c9bace565829d20a75