(bug 45084) update beta database automatically

This create a basic layout to create new jobs for the beta cluster. They
should be tied to Jenkins slave 'deployment-bastion' which is provided
by the new `beta` default.

The job run `mwscript update.php` every hour for the enwiki database.

Change-Id: Ib49518068f91232ab074a3bfa8b8a63f6b54dc34