add rename to Update

src/components/Update.php

@@ -40,6 +40,11 @@ class Update extends \CComponent
         @rename($old, $new);
     }
 
+    public function remove($target)
+    {
+        @unlink($target);
+    }
+
     public function cleanDir($path, $includeDir = false, $initPath = false)
     {
         if (!$initPath) {