Refund created for uncompleted payments

[bitberry-dev]

Steps to reproduce

1. Create order with check payment method.
2. Create refund in admin -> order -> payments.

Expected behavior

I expect error when creating refund from uncompleted payment. Also do not show refund icon for uncompleted payments and do not run refunds#new action.

Actual behavior

Refund created for payment in "invalid" state.

System configuration

Solidus Version:

"2.8.0.alpha" master, latest commit 622aa25e6c351c4de16af87e9cba70de596ad959

Is this the right behavior? If not I can fix it. Also refund model doesn't validate amount on updates.

[kennyadsl]

I don't think it is expected, it does not make sense to refund a payment that never happened. Feel free to submit a patch, thanks!