Add a property "IsFavorite" for the drop zone.

Back/skydiveLogs-api.Data/DropZoneRepository.cs

@@ -27,6 +27,11 @@ namespace skydiveLogs_api.Data
             return _col.FindById(new BsonValue(id));
         }
 
+        public bool Update(DropZone updatedDz)
+        {
+            return _col.Update(updatedDz);
+        }
+
         private readonly IDataProvider _dataProvider;
 
         private readonly LiteCollection<DropZone> _col;