feat:Make guake use the system default theme

[Davidy22]

Detect system theme by default like other gtk programs. Some misc setup/cleanup changes in the fork as well.

[gsemet]

For this on I let you fix the pipeline and switch back to norminal review, merge

[Davidy22]

Maybe the travis thing is just there from before, still not going away. I'll fix something on the issues list and see if a new pr still has it.

[gsemet]

ok, found it :D

[mlouielu]

Seems some black format issue:

https://github.com/Guake/guake/pull/1874/checks?check_run_id=3532130826#step:5:414

would reformat /home/runner/work/guake/guake/guake/prefs.py
Oh no! 💥 💔 💥
1 file would be reformatted, 32 files would be left unchanged.

[gsemet]

make style is your friend.

[mlouielu]

I've put a separate PR for coding style: #1880

[Davidy22]

Oh whoops, left it while it was running because I thought it was going to pass. Well, ran black on this and the other one now, and I'll stick around to check that it passes this time. Was just some whitespace thing though according to the diff

[Davidy22]

Oh, is there some nonsense I have to do with regenerating the reno file? I'll get to figuring that out

[Davidy22]

Some bizarre nonsense where python setup.py sdist works before I commit a slug file but breaks after. I'll figure this out eventually

[Davidy22]

Alright, figured it out, I just messed up formatting on the slug file

[mlouielu]

Can you rebase and check if the coding style may changed by black?

[Davidy22]

Changes in one file, fixed up now.

[gsemet]

And merged as well !