Propose a spec for Rally-as-a-Service
Propose a spec for Rally-as-a-Service

This spec covers a bunch of proposed patches:

 * https://review.openstack.org/#/c/336636/
 * https://review.openstack.org/#/c/182245/
 * https://review.openstack.org/#/c/279194/

Change-Id: I60b4b9a2eba140828b938814db8aba3ac7d78eef

openstack/rally,openstack/rally,yeming233/rally,yeming233/rally,openstack/rally,openstack/rally