Tente avec doctrine-bundle 2.0...

composer.json

@@ -31,7 +31,7 @@
   "require": {
     "php": "^7.1",
     "ext-json": "*",
-    "doctrine/doctrine-bundle": "^1.6",
+    "doctrine/doctrine-bundle": "^1.6|^2.0",
     "doctrine/orm": "^2.5",
     "psr/container": "^1.0",
     "symfony/config": "^3.0 | ^4.0",