Fix on AVG feedback calculation

Change-Id: Icf09f3891f1b4f9d778826750f6ea591fdaf4f09

app/Libs/utils/JsonUtils.php

@@ -59,7 +59,7 @@ abstract class JsonUtils
     public static function toJsonFloat($value)
     {
         if(empty($value)) return null;
-        return number_format(floatval($value),2);
+        return floatval(number_format(floatval($value),2));
     }
 
     /**

app/Models/summit/Presentation.php

@@ -46,6 +46,8 @@ class Presentation extends SummitEvent
         'ModeratorID'   => 'moderator_speaker_id:json_int',
         'Level'         => 'level',
         'AllowFeedBack' => 'allow_feedback:json_boolean',
+        'AvgFeedbackRate' => 'avg_feedback_rate:json_float',
+        'Published'       => 'is_published:json_boolean',
     );
 
     /**