Added NextAiring to Series (ResultColumn), which is used for Series/Index. Added tests and fixed broken tests after adding new property.

NzbDrone.Core/Repository/Series.cs

@@ -61,5 +61,8 @@ namespace NzbDrone.Core.Repository
 
         [ResultColumn]
         public int SeasonCount { get; set; }
+
+        [ResultColumn]
+        public DateTime? NextAiring { get; set; }
     }
 }