Bump flake8-isort from 2.7.0 to 2.8.0 in /{{cookiecutter.app_name}}

Bumps [flake8-isort](https://github.com/gforcada/flake8-isort) from 2.7.0 to 2.8.0.
- [Release notes](https://github.com/gforcada/flake8-isort/releases)
- [Changelog](https://github.com/gforcada/flake8-isort/blob/master/CHANGES.rst)
- [Commits](https://github.com/gforcada/flake8-isort/compare/2.7.0...2.8.0)

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

{{cookiecutter.app_name}}/Pipfile

@@ -55,6 +55,6 @@ flake8 = "==3.7.9"
 flake8-blind-except = "==0.1.1"
 flake8-debugger = "==3.2.1"
 flake8-docstrings = "==1.5.0"
-flake8-isort = "==2.7.0"
+flake8-isort = "==2.8.0"
 isort = "==4.3.21"
 pep8-naming = "==0.9.1"