code: function allow(action, req, res, cb) {
  		// call the allow method in our options if it exists
  		// or we will just assume it is always allowed
  		if (options.allow) {
  			return options.allow.apply(this, arguments);
  		}
  
  		return cb && cb(null, true);
  	}
docs: calls a method called 'allow' in our options that will
  perform any access checking
  
  @author Tim Golen 2015-03-01
  @access private
  
  @param  {string} action the CRUD actions being done
  @param  {object} req an Express or Restify Request object
  @param  {object} res an Express or Restify Response object
  @param  {Function} cb
  if request is allowed, cb(null, true)
  if request is not allowed, cb(null, false)
  
  @return {void}