Fix updateCalendarItems return

Author: Garethp

src/Calendar/CalendarAPI.php

@@ -173,7 +173,7 @@ public function updateCalendarItem(Type\ItemIdType $itemId, $changes)
             'SendMeetingInvitationsOrCancellations' => 'SendToNone'
         );
 
-        $items =  $this->updateItems($request, $options);
+        $items =  $this->updateItems($request, $options)->getCalendarItem();
 
         if (!is_array($items)) {
             $items = array($items);