Created cart

Created basket and line_items

Created working basket

Created ability in cart to show more then one same product at one line

Fixed problem with showing cart

Created showing cart with price and quantity

Created showing cart on main page with all functionality

Added ability to cart to show it when item add to cart and hide from back panel when cart is empty

Added ability to add to cart utem by clicking on its image
Merge pull request #5 from MavkaPoltavka/basket

Created cart