CHG: updated fixtures.
ADD: common fields.
ADD: migrations for festival application.
ADD: south migrations requirement on development env.
More close to definition:

* ADD: cancellation field + query set on ticket.
* CHG: price calculation.
* ADD: price x band x night.
* ADD: festival base price.
* ADD: discount calculations.
* ADD: links in change list for models.
* ADD: more base requirements.