WebSocket support

[SemanticBeeng]

Would you consider porting this https://github.com/Spinoco/fs2-http/blob/series/0.4/src/main/scala/spinoco/fs2/http/websocket/WebSocket.scala.

The use of web socket s and FS2 gives a nice streaming semantics when http/2 is cannot be used.

[pepegar]

Currently I don't have a lot of time to put into OSS.

However, I'd be more than happy to help if you want to contribute the websockets module in hammock ;)

[SemanticBeeng]

Oki.
Just looking for a review to determine if it could fit or it conflicts with something.