Add third argument to diffForHumans to match Carbon\Carbon

Carbon\Carbon::diffForHumans(Carbon\Carbon $other = NULL, $absolute = false, $short = false) has a new third argument and lack of it in Jenssegers\Date\Date::diffForHumans is not playing nicely.

src/Date.php

@@ -96,7 +96,7 @@ public static function createFromFormat($format, $time, $timezone = null)
      * @param  bool   $absolute Removes time difference modifiers ago, after, etc
      * @return string
      */
-    public function diffForHumans(Carbon $since = null, $absolute = false)
+    public function diffForHumans(Carbon $since = null, $absolute = false, $short = false)
     {
         // Get translator
         $lang = $this->getTranslator();