Updated order class and added in an order item class

this allows for the purchasing of multiple items in one order
#17

StockTrackerCommon/Models/Order.cs

@@ -9,12 +9,11 @@ namespace StockTrackerCommon.Models
     public class Order
     {
         public Order() { } 
+
         public string OrderId { get; set; }
         public string CustomerId { get; set; }
         public string SupplierId { get; set; }
-        public string ProductId { get; set; }
-        public string Quantity { get; set; }
-        public decimal UnitPrice { get; set; }
+        List<string> OrderItemIds { get; set; }
         public decimal TotalPrice { get; set; }
         public string OrderNotes { get; set; }
     }

StockTrackerCommon/Models/OrderItem.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StockTrackerCommon.Models
+{
+    public class OrderItem
+    {
+        public OrderItem() { }
+
+        public string OrderItemId { get; set; }
+        public string ProductId { get; set; }
+        public string Quantity { get; set; }
+        public decimal OrderPrice { get; set; }
+    }
+}