Drop django_openstack_auth from requirements.txt
Drop django_openstack_auth from requirements.txt

django_openstack_auth has been merged into horizon tree
as an effort of blueprint merge-openstack-auth.
There is no need to depend on django_openstack_auth any more.

Change-Id: Ieed8ce8526ace447c23e1daabf560381b5898949

openstack/trove-dashboard,openstack/trove-dashboard,openstack/trove-dashboard,openstack/trove-dashboard