Redirect to customer details page should not depend on order state.

The problem with the current method is twofold:

1. It does not account for any states that occur after the order has been created, specifically 'awaiting_return' and 'returned' . The latter causes a problem because it is impossible to then go to payments to refund the money if items have been returned in an RMA. Adding those 2 states to the current ```unless``` statement seems like a code smell.

2. It assumes the implementer has not modified the checkout steps; it essentially binds people to the checkout steps that are there by default.

In general, it seems like we should only be concerned with the presence of the billing address before we create a new payment.