Maybe we should use the payment_method as the engine name, for example: 'balanced_creditcard.

We are current not using the payment_choice. Just discovered that.
```
Contribution.where('payment_choice is not null')
=> #<ActiveRecord::Relation []>
```
These are the current payment methods in our database.
```
Contribution.where('payment_method is not null').map(&:payment_method).uniq
=> ["AuthorizeNet", "PayPal", "PrePopulate", "MoIP", "eCheckNet"]
```