Remove dependency on websocket-server

[Emelia Smith]

Hi, Just to let you know, the other week after 6 months of deprecation, and 3 years of no work, I unpublished websocket-server. I can see this project hasn't had any activity in 7 months, but I thought there may just be a chance that you care for it to still work. I'd recommend switching to the ws module, which provides a very similar interface to websocket-server.

[Claudio Cicali]

Thank you very much for the heads up!

I will update this asap.