Logger config

'logger' => function ($sm) {
  	$logger = new Zend\Log\Logger();
	$writer = new Zend\Log\Writer\Stream(APP_PATH . '/data/logs/app.log');
	$formatter = new Zend\Log\Formatter\Simple(
		'%timestamp% %priorityName% (%priority%): %message%',
		'd.m.Y H:i:s');
	$writer->setFormatter($formatter);
	$logger->addWriter($writer);

	// Capture PHP errors
	Zend\Log\Logger::registerErrorHandler($logger);
	Zend\Log\Logger::registerExceptionHandler($logger);

	return $logger;
},