Added munin client role
Added munin restart to fix notification bug
Added munin client handlers
Ensure munin-node service is running and starts on boot
Added default variables for mnin client
Added munin-node config file template
Added iptable rules for munin-node client
Ignore munin group_var files
Updated monitor playbook to include munin role
Updated hosts example to include all available roles
Updated readme to include munin role