Return back devstack exercise to in-tree plugin
Return back devstack exercise to in-tree plugin

It'll be executed on the post devstack installation stage to ensure
sahara service running.

Change-Id: I299afd3382113b3b088f8feb87c40d5f632c62f1

tellesnobrega/sahara,crobby/sahara,zhangjunli177/sahara,egafford/sahara,openstack/sahara,ekasitk/sahara,crobby/sahara,zhangjunli177/sahara,egafford/sahara,ekasitk/sahara,tellesnobrega/sahara,zhangjunli177/sahara,crobby/sahara,openstack/sahara,ekasitk/sahara