Add tests/ to refactor by Rector

Author: kenjis

rector.php

@@ -53,6 +53,7 @@
     // The paths to refactor (can also be supplied with CLI arguments)
     $rectorConfig->paths([
         __DIR__ . '/src/',
+        __DIR__ . '/tests/',
     ]);
 
     // Include Composer's autoload - required for global execution, remove if running locally