use decimal for dish prices

BeckmanComms.Api.DataTransferObjects/V2/Cafe/DishDto.cs

@@ -35,12 +35,12 @@ namespace BeckmanComms.Api.DataTransferObjects.V2.Cafe
         /// <summary>
         /// The standard price of the dish.
         /// </summary>
-        public double StandardPrice { get; set; }
+        public decimal StandardPrice { get; set; }
 
         /// <summary>
         /// The price of a half-order of the dish, when available.
         /// </summary>
-        public double? HalfPrice { get; set; }
+        public decimal? HalfPrice { get; set; }
 
         /// <summary>
         /// Indicates whether the item is available every day ( <c>DishDto.Specialty == false</c>) or