Add manual job triggering script.

Change-Id: Ic396c845e5f61a98d3b0e8c3fc08c6f9dbfffc6a
Reviewed-on: https://review.openstack.org/34437
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins