Blocking version 1.1.6 of django_openstack_auth

The release of django_openstack_auth 1.1.6 introduced a change that
is not compatible with the stable/havana release. All gate jobs
are blocked until this is fixed.

Partial-bug: #1332855
Change-Id: I40ef4583df47d3219c17d481f466c96e1d8baca8