add doctrine/orm as a dependency for dev

Author: AlexeyKosov

composer.json

@@ -7,9 +7,12 @@
     "require": {
         "php": "^7.1",
         "symfony/framework-bundle": "^4.0|^5.0",
-        "friendsofsymfony/elastica-bundle": "^5.0|^6.0",
+        "friendsofsymfony/elastica-bundle": "^6.0",
         "enqueue/enqueue-bundle": "^0.10"
     },
+    "require-dev": {
+        "doctrine/orm": "^2.0"
+    },
     "autoload": {
         "psr-4": { "Enqueue\\ElasticaBundle\\": "" }
     },