Bump flake8 from 3.4.1 to 3.7.7
Bump flake8 from 3.4.1 to 3.7.7

Bumps [flake8](https://gitlab.com/pycqa/flake8) from 3.4.1 to 3.7.7.
- [Release notes](https://gitlab.com/pycqa/flake8/tags)
- [Commits](https://gitlab.com/pycqa/flake8/compare/3.4.1...3.7.7)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
glidernet/python-ogn-client