Add support for RedHat/Suse based systems

Although untested 'this should work'. The command is taken from the Fedora
instructions on [1] which look from a quick search around like they work on
RHEL and equivalents.

[1] http://wiki.cacert.org/FAQ/ImportRootCert#Linux

I will test this at some point but for now this visual check will do.

Ansible dependency is now 1.4 so we can use include_vars.
Remove dead code

This was a failed attempt to get the variables importing and slipped in the the
last commit.