Update to Websocket V13

[tomaszchacuk]

Is there a chance of upgrading to websockets V13 and add masking feature ?

[ikaras]

Hi, @tomaszchacuk.
Sorry, but I'm busy on the other commercial project for the next 6 months and can't make upgrading :(
If you familiar with it and you can implement it I'll merge your commit into repository with pleasure.

[comboy]

I'm not making PR since it's not well tested and I have no idea about backwards compatibility, but
here's a quick fix @tomaszchacuk:

https://gist.github.com/comboy/f6d7084fa3740cda3f3461d2c5c89a88

Just replace ws_encode.lua with this. It sets the mask bit and adds mask consisting of 0 bits (I don't think anything more is really needed for nodemcu client)

Works for me with V13 server, but as mentioned, don't trust it too much.