[Bitstamp] include txid in toString()

[tross-nydig]

Small followup to the recent PR that added txid to the WithdrawalRequest object.

[bigscoop]

Hi. Please use @ToString from lombok and delete the method toString()

[tross-nydig]

Hi. Please use @ToString from lombok and delete the method toString()

Great idea, the previous toString() also included the additional derived status enum (i.e. status=finished) but I was able to keep it in there by using the @ToString.Include annotation.