Use fstrings

[taylorjdawson]

Fstrings = syntatic surgar + speed.

How do you guys feel about switching .formats and % to fstrings?

[AndreMiras]

I love fstring but it's only from Python 3.6, so it means we don't even support Python 3.5? It might be a bit too much for a library no? Unless we have it available from __future__.

[corpetty]

While I also love fstrings, I'd like to make sure its compatible to at least 3.5. Many people still use that.

[taylorjdawson]

Would this be a possibility?

[AndreMiras]

Yes I've read about it, but the author himself said it was hacky. It's tagged hack in GitHub and he said it's "terrible" on Stackoverflow https://stackoverflow.com/a/46225926/185510.