Pass module name (e.g. models.mail) in the config as 'module' property.

Pass the rig module name (eg. controllers.user, models.mail) as `module` property in the config, so we can use it for loggin like:
````
module.exports = function (config) {
    var moduleName = config.module,
...
   log.debug(moduleName, 'Something happened');
// prints [debug] models.mail Something happened
```