php8 compatibility

[gturri]

According to dc87f31 http-mock is compatible with PHP8. It would be really cool to release a package which updates this constraint in order to be able to use http-mock on a CI running on this version of PHP8.
Is it something you could consider doing?

[4d4ch4u32]

I would also like to use it, in a PHP 8 project.

[dudapiotr]

Any progress to merge it into master?