Upgrade dependencies to newer versions

[saamorim]

Current danger-python dependencies are too outdated and create all sorts of dependency "hells". For instance, newer versions of black require newer versions of click.

[orta]

Seems reasonable to me, but I don't use this 👍🏻

[saamorim]

@orta what don't you use? black and click?

[orta]

I've not used danger-python, and I also don't know what black or click are too :D