Adds double booking prevention to API. If a booking that would be created overlaps with an existing booking for the same bookable we now return 409 (Conflict) instead of making a double booking.
Race condition tests coming in a separate follow-up PR.
Adds double booking prevention to API. If a booking that would be created overlaps with an existing booking for the same bookable we now return 409 (Conflict) instead of making a double booking.
Race condition tests coming in a separate follow-up PR.