16.7.0-alpha.2 warning

[dancrew32]

Trying out react "react": "^16.7.0-alpha.2".

This project is currently on alpha.0.

https://github.com/mfrachet/use-socketio/blob/master/package.json#L36

I think these empty array literals as the second argument of useEffect are deprecated.

https://github.com/mfrachet/use-socketio/blob/d156cd954db952998f4bb3747f71df40bb58e5f3/src/useSocket.js#L9

https://github.com/mfrachet/use-socketio/blob/1fcd3d839fd0e3247c0dcd644d364275738e4a94/README.md#L25

https://github.com/mfrachet/use-socketio/blob/1fcd3d839fd0e3247c0dcd644d364275738e4a94/example/src/components/Feed.js#L21

The result in this warning:

react-dom.development.js:506 Warning: useEffect function must return a cleanup function or nothing.
    in Router (created by App)
    in r (created by App)
    in App
warningWithoutStack @ react-dom.development.js:506
commitHookEffectList @ react-dom.development.js:16041
commitPassiveHookEffects @ react-dom.development.js:16055
callCallback @ react-dom.development.js:149
...

I think the clean up function protocol may have changed?

https://reactjs.org/docs/hooks-effect.html#example-using-hooks-1

Edit: I see that they are memoized callbacks, so nevermind!.