Terminal color detection on Linux is wrong

[meator]

Hi. Colored logs weren't shown on my terminal (alacritty). I have tried to set loguru::g_colorlogtostderr to both true and false, but nothing. I have investigated this further and then I came across this:

https://github.com/emilk/loguru/blob/master/loguru.cpp#L231-L243

That's not how you detect color support in terminals. (N)Curses should be used. The current solution is a hack.

If that is not feasible, the list should at least be expanded. I could make a PR for that.