Bump django from 1.11.23 to 1.11.28 Bumps [django](https://github.com/django/django) from 1.11.23 to 1.11.28. - [Release notes](https://github.com/django/django/releases) - [Commits](https://github.com/django/django/compare/1.11.23...1.11.28) Signed-off-by: dependabot[bot]