Add customer communication system

LittleShop.Client/LittleShopClient.cs

@@ -9,6 +9,7 @@ public interface ILittleShopClient
     IAuthenticationService Authentication { get; }
     ICatalogService Catalog { get; }
     IOrderService Orders { get; }
+    ICustomerService Customers { get; }
 }
 
 public class LittleShopClient : ILittleShopClient
@@ -16,14 +17,17 @@ public class LittleShopClient : ILittleShopClient
     public IAuthenticationService Authentication { get; }
     public ICatalogService Catalog { get; }
     public IOrderService Orders { get; }
+    public ICustomerService Customers { get; }
     
     public LittleShopClient(
         IAuthenticationService authenticationService,
         ICatalogService catalogService,
-        IOrderService orderService)
+        IOrderService orderService,
+        ICustomerService customerService)
     {
         Authentication = authenticationService;
         Catalog = catalogService;
         Orders = orderService;
+        Customers = customerService;
     }
 }