Depend only on OpenStack Swift 1.9.1

* The master branch is currently tracking the development
version 1.9.1 of Havana OpenStack Swift.

* Seems that we still have some settings which are not
reset in the unit tests.  This fix provides a guaranteed
state for test_utils.py:TestUtils.test_get_container_details

Change-Id: Ie32f49743301bfa493f70ed8a539fb6840f9f67b
Signed-off-by: Luis Pabon <lpabon@redhat.com>
Reviewed-on: http://review.gluster.org/5719
Reviewed-by: Peter Portante <pportant@redhat.com>
Tested-by: Peter Portante <pportant@redhat.com>