Bump flake8 from 3.7.6 to 3.7.7 (#545)

Bumps [flake8](https://gitlab.com/pycqa/flake8) from 3.7.6 to 3.7.7.
- [Release notes](https://gitlab.com/pycqa/flake8/tags)
- [Commits](https://gitlab.com/pycqa/flake8/compare/3.7.6...3.7.7)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Pipfile

@@ -12,7 +12,7 @@ name = "pypi"
 [packages]
 
 BeautifulSoup = "==3.2.1"
-flake8 = "==3.7.6"
+flake8 = "==3.7.7"
 flake8-isort = "==2.6.0"
 mozlog = "==4.0"
 PyPOM = "==2.2.0"