Make trebuchet work in eqiad.wmflabs

Update the role::deployment::deployment_servers::labs role to work in
the eqiad labs environment.

* Don't create the "trebuchet" user in labs
* Make "trebuchet" the owner or /srv/deployment
* Allow 10/8 to access the apache vhost
* Fix grain selector for refresh_* commands to include
  'G@deployment_server:true'
* Add top.sls configuration for grain 'deployment_server:true'

Change-Id: Ie89deed31031b53742a0d5f0fd4cd0e82e21438e