updated properties of extensions

Nav.php

@@ -14,7 +14,7 @@ use yii\helpers\Html;
 
 /**
  * Nav renders a nav HTML component.
- * 
+ *
  * For example:
  *
  * ```php
@@ -37,12 +37,12 @@ use yii\helpers\Html;
  *     ],
  * ]);
  * ```
- * 
+ *
  * Note: Multilevel dropdowns beyond Level 1 are not supported in Bootstrap 3.
- * 
+ *
  * @see http://getbootstrap.com/components.html#dropdowns
  * @see http://getbootstrap.com/components/#nav
- * 
+ *
  * @author Antonio Ramirez <amigo.cobos@gmail.com>
  * @since 2.0
  */