Unlocked dependencies and possibly issue with custom-menu example

[flash1293]

It makes sense to lock down the depenencies by checking in the package-lock.json and maybe even yarn.lock files.

This could prevent non-repeatable builds further down the line. I suspect there is already an issue with this - a fresh checkout with npm install && npm start gives me the attached behavior in the custom-menu example. The same example on https://reactcommunity.org/react-autocomplete/custom-menu/ looks fine. (macOS 10.13.3, Chrome 66.0.3354.0)

http://localhost:8080/custom-menu/:

https://reactcommunity.org/react-autocomplete/custom-menu/

[flash1293]

It works fine for me locally with version 1.7.3, maybe https://reactcommunity.org/react-autocomplete/custom-menu/ isn't updated yet.