fixup! src: Set up an inventory helper

public/index.php

@@ -21,7 +21,7 @@ $app->get('/inventory/{item}', function (Request $request, Response $response, a
  */
 $container = $app->getContainer();
 
-$container['logger'] = function (Slim\Container $c) {
+$container[Logger::class] = function (Slim\Container $c) {
     $logger = new \Monolog\Logger('inventory-logger');
 
     $logger->pushProcessor(new \Monolog\Processor\PsrLogMessageProcessor());