Adding date type for X-Editable

Twig/Extension/SonataAdminExtension.php

@@ -352,6 +352,7 @@ class SonataAdminExtension extends \Twig_Extension
             'currency'   => 'number',
             'percent'    => 'number',
             'url'        => 'url',
+            'date'       => 'date',
         );
 
         return isset($mapping[$type]) ? $mapping[$type] : false;