contau, maria und adminer up and running

development-system/composer.json

@@ -5,6 +5,8 @@
   "require": {
     "contao/managed-edition": "^5.3"
   },
+  "minimum-stability": "dev",
+  "prefer-stable": true,
   "scripts": {
     "post-install-cmd": [
       "Contao\\ManagerPlugin\\Bundle\\Config\\ScriptHandler::initializeApplication"