Add setup for lorry mirroring server

Based on issue GNOME/gnome-build-meta#301 (closed), the setup is added to create a lorry server for mirroring build dependencies. The machine is the one supplied re Infrastructure#697 (closed).

The lorry-controller is currently set up and running on the machine and has been shown to work with the test config located here.

The access key is currently a temporary one associated with my account and will expire in 5 days from now. A new access key needs to be generated re Infrastructure#705 (closed). This should be associated with a lorry user and should have full permissions to create groups and push to the Infrastructure/Mirrors namespace.

This access key will need putting into the ansible vault and will need to be associated with the variable lorry_automation_user_api_token in file inventory/group_vars/lorry-servers.