Bump django from 2.2.7 to 2.2.8

Bumps [django](https://github.com/django/django) from 2.2.7 to 2.2.8.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@2.2.7...2.2.8)

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

requirements.txt

@@ -9,7 +9,7 @@ certifi==2019.11.28
 chardet==3.0.4
 ddtrace==0.31.0
 defusedxml==0.6.0
-Django==2.2.7
+Django==2.2.8
 django-allauth==0.40.0
 django-bulma==0.6.0
 django-redis==4.10.0