/**
  * @throws \Exception
  * @return string
  */
 protected function _getMigrationsDir()
 {
     $migrationsDir = Tools::getMigrationsPath();
     if (!file_exists($migrationsDir)) {
         if (!@mkdir($migrationsDir)) {
             throw new \Exception("Unable to create migration directory on " . Tools::getMigrationsPath());
         }
         @chmod($migrationsDir, 0777);
     }
     return $migrationsDir;
 }