Bump django from 2.1.2 to 2.2.13

Bumps [django](https://github.com/django/django) from 2.1.2 to 2.2.13.
- [Release notes](https://github.com/django/django/releases)
- [Commits](https://github.com/django/django/compare/2.1.2...2.2.13

)

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