This changes introduces the command `overcloud node provision` that takes a file with roles, deployes the requested nodes and creates an environment file. See the spec for details: http://specs.openstack.org/openstack/tripleo-specs/specs/stein/nova-less-deploy.html Change-Id: I806fcbdabf0bb93fa222f3fa76944f0f50267011 Depends-On: https://review.openstack.org/637191 Implements: blueprint nova-less-deploy