Add memo to the payment resource

[jedmccaleb]

[sacarlson]

if your going to add memo data to the stream data at some point, I hope you also add the created_at time stamp info in it also. Also the tx_id code might be good to add, but I can get that from the link that has the id in it already. It's just a bit more work to extract the number when needed.

example of code that creates this stream: var future_payments = server.payments() .forAccount(account.value) .cursor(0) .stream({onmessage: handlePaymentResponse});