Add missing param visibility for snippet creation

Author: mirko-jtl

lib/Gitlab/Api/Snippets.php

@@ -28,12 +28,13 @@ public function show($project_id, $snippet_id)
      * @param string $code
      * @return mixed
      */
-    public function create($project_id, $title, $filename, $code)
+    public function create($project_id, $title, $filename, $code, $visibility)
     {
         return $this->post($this->getProjectPath($project_id, 'snippets'), array(
-            'title' => $title,
-            'file_name' => $filename,
-            'code' => $code
+            'title'      => $title,
+            'file_name'  => $filename,
+            'code'       => $code,
+            'visibility' => $visibility
         ));
     }