Added refreshed since for channels

YTManager/Models/Channel.cs

@@ -30,6 +30,10 @@ namespace YTManager.Models {
         [Required]
         public DateTime AddedtoDB { get; set; }
 
+        //! Last time this channel was updated.
+        [Required]
+        public DateTime Refreshed { get; set; }
+
         // Videos this channel has.
         public List<Video> Videos { get; set; }
     }