Updated openstack/openstack
Project: openstack-infra/devstack-gate  6cec2d8b5280f8958f8a0c7587dcd8751c5f78f7
null
Add change in README file according to changes in code

Manifest slave_template.pp was renamed single_use_slave.pp
This change added to README file.

Change-Id: I5168cba9e4a87c10f83728e99198a3e55e1d06f7