Since packer version 1.2.5, packer now supports pulling openstack
config from clouds.yaml. Let's consolidate to that file so that we
don't have duplicate configuration with the jobs that need the
openstack cli.
Issue: RELENG-1205
Change-Id: Idf23a30b111dd922120fb6195d0411e2fc993dab Signed-off-by: Thanh Ha <thanh.ha@linuxfoundation.org>