I think I have to send 3 messages to the websocket
to initialise it. In response, it seems to send the last
ticker price reasonably quickly, compared to earlier
when it was just waiting for the next available transaction
before notifying me.
It seems to work but I think the ticker value returned
by the remote call is wrong. Maybe I'm calling the wrong
endpoint ¯\_(ツ)_/¯ I don't know trying to work it out