Disable iptables on AWS.

This will do 3 things;
* Prevent rules from being written via `iptables_ng_rule`
* Remove the default `REJECT` rule from `/etc/sysconfig/iptables`
* Stop and disable the service.
Skip iptables in soho as well.
Merge pull request #1 from behanceops/feature-skip-aws

Disable iptables on AWS.