Oscar 0.7.1 release notes

This is Oscar 0.7.1, a small release to squash one gremlin in 0.7 that affects django-oscar-paypal.

Bug fixes

This release makes a change to the checkout session mixin which allows a basket to be explicitly specified by subclasses of the checkout PaymentDetails view class. This is required when a different basket to request.basket is intended to be used in a preview (this is what django-oscar-paypal needs to do).