Project boards: remove $parameters param, not neccesary!

It was added by mistake, in https://docs.gitlab.com/ee/api/boards.html
there is no defined any query param for project boards.

Author: omarlopesino

lib/Gitlab/Api/Projects.php

@@ -371,9 +371,9 @@ public function issues($project_id, $parameters = array())
      * @param int $project_id
      * @return mixed
      */
-    public function boards($project_id, $parameters = array())
+    public function boards($project_id)
     {
-        return $this->get($this->getProjectPath($project_id, 'boards'), $parameters);
+        return $this->get($this->getProjectPath($project_id, 'boards'));
     }
 
     /**