used controller_path instead of controller: "<controller>", action: "<action>" in link_to in application layout
created cart scaffold
migrated create_carts
created current_cart method in application_controller to get or set the current cart
added migration to add cart_id to line_item
migrated cart_id to line_item
added a relationship between album, cart, and line_item and made sure an album is not referenced by any line_item before it is destroyed
added line_item controller
added line_items to routes and created 'Add to Cart' button
added notice to line_items
added migration to add default quantity to line_item to 1
migrated create_default_value_to_quantity
added public albums to menu
added add_album method in cart_controller to check if album is already in cart
added few albums in cart