Bump flake8 from 3.7.7 to 3.7.8 in /{{cookiecutter.app_name}} (#516)

Bumps [flake8](https://gitlab.com/pycqa/flake8) from 3.7.7 to 3.7.8.
- [Release notes](https://gitlab.com/pycqa/flake8/tags)
- [Commits](https://gitlab.com/pycqa/flake8/compare/3.7.7...3.7.8)

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

{{cookiecutter.app_name}}/Pipfile

@@ -50,7 +50,7 @@ pdbpp = "==0.10.0"
 
 # Lint and code style
 black = "==19.3b0"
-flake8 = "==3.7.7"
+flake8 = "==3.7.8"
 flake8-blind-except = "==0.1.1"
 flake8-debugger = "==3.1.0"
 flake8-docstrings = "==1.3.0"