Add missing env var to phpunit config

Author: alcaeus

phpunit.xml.dist

@@ -11,6 +11,7 @@
     <php>
         <ini name="display_errors" value="1" />
         <ini name="error_reporting" value="-1" />
+        <env name="MONGODB_PRIMARY_URL" value="mongodb://localhost:27017" />
         <server name="APP_ENV" value="test" force="true" />
         <server name="SHELL_VERBOSITY" value="-1" />
         <server name="SYMFONY_DEPRECATIONS_HELPER" value="max[self]=0" />