Add OpenStack favicon to status page

Initial addition of OpenStack favicon to status index, if
we like it the html can be updated on related sites to
include it elsewhere in what we host.

Change-Id: I63df3f47f8c9e2f4a8fddf9abfe002f6d9721586
Reviewed-on: https://review.openstack.org/30568
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Khai Do <zaro0508@gmail.com>
Approved: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins