Check for firewall and host.allow/deny rules

[tvinhas]

Just had a ticket from a customer that used chef_stack to install Chef-backend but it failed.
After some digging, he found out the problem was the custom host.allow and host.deny rules he had.

Would be nice to have some preflight check or even better if the cookbook could add the necessary rules on iptables and host.* with the required ports enabled.

[stephenlauck]

This would be a great thing to add to the preflight checks we are doing with Inspec for chef installs. Here is an example of one https://github.com/stephenlauck/preflight_chef_server_inspec_profile