Added flake8 to requirements.txt
Added flake8 to requirements.txt

Turbo87/skylines,skylines-project/skylines,shadowoneau/skylines,Harry-R/skylines,Harry-R/skylines,shadowoneau/skylines,kerel-fs/skylines,Harry-R/skylines,snip/skylines,TobiasLohner/SkyLines,skylines-project/skylines,Turbo87/skylines,TobiasLohner/SkyLines,Harry-R/skylines,skylines-project/skylines,snip/skylines,kerel-fs/skylines,skylines-project/skylines,Turbo87/skylines,RBE-Avionik/skylines,RBE-Avionik/skylines,TobiasLohner/SkyLines,snip/skylines,shadowoneau/skylines,Turbo87/skylines,RBE-Avionik/skylines,shadowoneau/skylines,RBE-Avionik/skylines,kerel-fs/skylines