(SHOPPING CART PAGE) Total per line price does not change after increase/decrease items

[ilsinyakov]

Pre-conditions:

1. At least one product is added to cart
2. Go to shopping cart page

Steps:

1. Click "Plus" button
2. Click "Minus" button

ER: Total per line price change after increase/decrease items and equal amount * unit price

AR: Total per line price does not change after increase/decrease items and equal unit price

FR:

Given: I am on a shopping cart with an added product When: I am decreasing/increasing quantity Then: Quantity of product changes, summary price change(in line and total in cart)

---

[ilsinyakov]

Tested Fixed Test: UI/test_shopping_cart.py