Treat 404 cases

Author: jdomenechb

composer.json

@@ -14,7 +14,8 @@
         "php": ">=7.0",
         "react/http": "^0.8.0",
         "symfony/http-foundation": "*",
-        "symfony/console": "*"
+        "symfony/console": "*",
+        "symfony/http-kernel": "*"
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^2.13"