[Infrastructure] [Firewall] Initial UFW provisioning

:construction_worker: Throwing this out there for #307. This is a work in progress and needs further refinement.

* [X] iptables rules for web servers
* [x] iptables rules for Jenkins
* [x] Disable all access on IPv6

There are some major issues I see with getting this locked in the way we want:

* Provisioning happens in 3 segments, we can't use that information to apply rules related to Jenkins (allow SSH to the web server from the Jenkins box)

According to https://github.com/rgbkrk/developer.rackspace.com/blob/iptables/deploy/prod_web.yml#L78, the webservers listen on port 80, not 8080. Perhaps we should use a shared variable for the port?