Valid ensure file resource value.

In case that **supervisor::service::ensure** is set to _present_ and **supervisor::service::enable** is set to _true_, value of **$config_ensure** will be set to _undef_. Possible values of **[file](http://docs.puppetlabs.com/references/latest/type.html#file)** resource **[ensure](http://docs.puppetlabs.com/references/latest/type.html#file-attribute-ensure)** property are _absent_, _present_, _file_, _directory_, and _link_.

Due to passing _undef_ instead of _file_ when creating _"${supervisor::conf_dir}/${name}${supervisor::conf_ext}"_ file resource creation of supervisor's configuration file will fail.