Use SensioFrameworkExtraBundle v6 (#6)

* Use SensioFrameworkExtraBundle v6

* Trigger CI

Author: Nyholm

composer.json

@@ -10,7 +10,7 @@
         "doctrine/doctrine-bundle": "^2.3",
         "doctrine/orm": "^2.8",
         "phpdocumentor/reflection-docblock": "^5.2",
-        "sensio/framework-extra-bundle": "^5.1",
+        "sensio/framework-extra-bundle": "^6.1",
         "symfony/asset": "*",
         "symfony/console": "*",
         "symfony/dotenv": "*",