Add ask.openstack.org to ssl certs we monitor

Added ask.openstack.org to the list of ssl certs we monitor,
also took the opportunity to alphabetize the list.

Change-Id: I251d6ee0df8b73f159a9d7844b5c89412a548919
Reviewed-on: https://review.openstack.org/31866
Reviewed-by: James E. Blair <corvus@inaugust.com>
Reviewed-by: Dan Prince <dprince@redhat.com>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins