Full payment release should not require amount

[szilardd]

Based on documentation (https://reference.assemblypayments.com/?csharp#release-payment) when releasing a payment, you need to specify an amount if you want to do a partial release.

But if you want to do a full release, this should be optional because if there are fees involved, you don't really know the full amount available.

Shouldn't the amount be optional here or another overload wihout the releaseAmount parameter ? https://github.com/AssemblyPayments/promisepay-dotnet/blob/master/PromisePayDotNet/Interfaces/IItemRepository.cs#L39

The example request shown in the documentation seems to suggest this

var repo = container.Resolve<IItemRepository>();
repo.ReleasePayment("e57120ea-053d-11e6-b512-3e1d05defe78"); // no amount needed here

Thanks