2.0.0 pre-release version

[Nihisil]

@Apricot-S I'm going to release pre-release version on pypy, so it can be installed through default installation process. I mainly need that to test lib in my other small projects to find regressions. Do you have any concerns?

I have released other versions same way before: https://pypi.org/project/mahjong/#history

[Apricot-S]

I don't think there's a problem.

[Nihisil]

https://pypi.org/project/mahjong/2.0.0.dev1/ was released

[Apricot-S]

@Nihisil
Could you please release v2.0.0.dev2?
I'd like to check if the URLs to the wiki and documentation work.

[Nihisil]

https://pypi.org/project/mahjong/2.0.0.dev2/ was released