Enforce type checking on the codebase

[motohedgehog]

It would be nice to make Nubia strictly type checked so projects that use it could rely on its type safety.

Most likely we'll have to support both mypy and Pyre.

[marimar96]

Hi @ylectric:
I would like to know if this means that the type check should be part of the tests or it should be implemented like some config.ini file on the root of the project and then someone run the, for example, mypy with that config file as an argument.
Although, I think it would be good to implement the type check in the pre-commit hook :)

[motohedgehog]

@marimar96, thanks for looking into this :)
The idea here is to enrol the code base into some type checking mechanism and eventually have it fully type annotated in strict mode.

The tricky part here is that we need to somehow align it with our internal infrastructure. For example, we'd prefer Pyre over mypy, but setting it up for both environments might be challenging.

P. S. I love the idea of having it as a pre-commit hook 👍🏻