address flake8 format check #100

Job	Run time
Build source distribution	12s
Build wheels on ubuntu-latest x86_64	15m 40s
Lint with flake8 and check black	6s
Build wheels on ubuntu-latest i686	16m 51s
Build wheels on ubuntu-latest aarch64	2h 14m 13s
Build wheels on ubuntu-latest ppc64le	2h 8m 24s
Build wheels on ubuntu-latest s390x	2h 3m 32s
Build wheels on macOS-latest x86_64	7m 38s
Build wheels on macOS-latest arm64	14m 4s
Build wheels on windows-2019 AMD64	9m 53s
Build wheels on windows-2019 x86	8m 28s
	7h 39m 1s

Provide feedback