Ordered params (config not retrocompatible) + tags + configuration validation + aditionnal configuration

The role now : 
- have compatibility with multiple "listen" and for ordered needed arguments like "allow" and "deny" (I change syntax from dict to list for that)
- change site configuration from /etc/nginx/conf.d to /etc/nginx/sites-available .
- had a symlink from /etc/nginx/sites-available to /etc/nginx/sites-enable.
- have a travis configuration
- have gestion for aditionnal configuration (convenient if you apply different set of rules to the same host)
- have tags (configuration, packages and service)