Bill change should be working

Reduce quantity should be working.

bookie/src/app/sales/products/products.component.ts

@@ -21,6 +21,6 @@ export class ProductsComponent implements OnInit {
   }
 
   addProduct(product: Product): void {
-    this.bs.addProduct(product);
+    this.bs.addProduct(product, 1, 0);
   }
 }