Add a zaqar-swift-backend environment file
Add a zaqar-swift-backend environment file

The main purpose of this file is to enable the zaqar service
but, unlike the environments/services/zaqar.yaml file it explicitely
disables the redis service as this is meant to be used with
swift/sqlalchemy.

The main use case here being the containerized undercloud

Change-Id: Ic11b4790a1a2c2336cd432784f19922e76e028ad
Partial-Bug: #1795027

openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates