basket update

http/basket.go

@@ -26,6 +26,8 @@ type GetBasketItemsResponse struct {
 	Price     float64       `json:"price"`
 	CreatedAt time.Duration `json:"created_at"`
 	UpdatedAt time.Duration `json:"updated_at"`
+
+	Error string `json:"error"`
 }
 
 type BasketCheckoutRequest struct {