Remove enforcement of warnings as errors

[SpaceIm]

Could you revert #211 please? It's terrible for package managers to force warnings as errors. Warnings as errors is for library developers, not for users of your library.

There is already an option to enable Warnings as errors, why would you want to prevent someone disabling this option?

I would also advise to not hardcode all these warnings. You could add an option to enable them, beccause again these warnings are for you, users don't care and it can be harmful.