This is the initail code that meets the kata/specification.

Improvments in the future could include:

• A database with all the prices
• Each item could have a quantity instead of being added to a List inside the scannedItems Map, this would allow only a SKU to be passed to the scanItem method and would reduce the overhead.
• A database with the discounts configure so that they can be configured separately and read into objects by the provider.
• Spring autowiring to allow things to be replaced for testing purposes

The assumptions made are:

• The price can be read as each item is scanned as this is a supermarket and the prices will not be updated in working hours.
• Discounts will follow the same principle.