Network: Add `interfaces.yaml`

The interfaces.yaml file is used by vcloud-net-spinner to apply rules to the
correct vShield Edge firewall. This commit adds an `interfaces.yaml` file to the
repository, and updates the URL appropriately.
Network: Add `firewall.rb`

This commit adds a `firewall.rb` file for use when configuring the vSE to work
with a new GOV.UK Off-site Backup machine in Carrenza.
Network: Add `jenkins.sh`

This commit adds a `jenkins.sh` file which allows for the Jenkinsisation of
network deployment jobs. The EdgeGateway's UUID has been changed to match the
`0E7T-IS-GATEWAY-002` EdgeGateway, so that rules deploy the right EG!
Network: Add `lb.rb`

This commit adds an `lb.rb` rulefile to control the load-balancing rules on the
vShield Edge firewall.
Network: Add `nat.rb`

The `nat.rb` file is a ruleset used to configure NAT rules on the vShield Edge
firewall. This commit adds this file.
Box: Add YAML file for use when launching boxes

The YAML file in this commit is used when launching new GOV.UK off-site backup
machines using `vcloud-launch`.
Box: Add `jenkins.sh` for use when launching boxes

This commit adds a `jenkins.sh` box for use when launching boxes using
`vcloud-launch` and a one-click Jenkinsified installation.