Security role should require an email to receive root's mail

[Major Hayden]

V-38680 requires that someone must receive root's email. There is not a hard requirement at the moment to set security_root_forward_email prior to running the security hardening role. There should be a pre-flight check that ensures this value is set.

I'd like some more input on how we can handle this without halting the playbook run since users might not understand that this is a required configuration item.

[Major Hayden (rackerhacker)]

RHEL 6 STIG content is now deprecated.