update doctrine/migration requirement to 3.0

Author: jderusse

composer.json

@@ -23,7 +23,7 @@
         "php": "^7.2",
         "symfony/framework-bundle": "~3.4|~4.0|~5.0",
         "doctrine/doctrine-bundle": "~1.0|~2.0",
-        "doctrine/migrations": "dev-master"
+        "doctrine/migrations": "~3.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^6.4|^7.0",