DJANGO-RACEWAY USER STORY: Checkout

## User Story:

As a **Site User** I can **checkout** so that I can **proceed with my order/booking**.

## Acceptance Criteria:

- Payments are handled by **Stripe** 
- You can **checkout as a guest** 
- **A confirmation email** is sent as well as **clear indication** on the site that your order went through successfully or not via **on-screen messages**
