PHP 8.0 support

[timonf]

Hey there!

I just like your library and I'm using it for simple key-value stores :)
I recently upgraded to PHP 8.0 on my local machine and discovered this is not supported by this library.

Timon

[predyke]

I am in the same shoes as you are. Currently I forked the repo and trying to add my own implementation it will turn out eventually If I manage to create a PR out of this.