Add opendev service-announce list

This way we can send a single email that our users can see if subscribed
to this list instead of sending emails to all of their discuss lists.

Change-Id: I3b978a3c4e7888f14e3986628cb29a6c86bbcf61

modules/openstack_project/manifests/lists.pp

@@ -499,4 +499,12 @@ class openstack_project::lists(
     password    => $listpassword,
     description => 'Collaborating on Network Based Media Processing related platform and infrastructure systems usage and development.',
   }
+
+  mailman_list { 'service-announce@opendev':
+    require     => Mailman::Site['opendev'],
+    ensure      => present,
+    admin       => 'cboylan@sapwetik.org',
+    password    => $listpassword,
+    description => 'Announcement list for OpenDev services.',
+  }
 }