Bump django from 2.1.5 to 2.2.24

Bumps [django](https://github.com/django/django) from 2.1.5 to 2.2.24.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@2.1.5...2.2.24)

---
updated-dependencies:
- dependency-name: django
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -8,7 +8,7 @@ colorama==0.4.3
 coreapi==2.3.3
 coreschema==0.0.4
 dj-database-url==0.5.0
-Django==2.1.5
+Django==2.2.24
 django-cors-headers==3.4.0
 django-filter==2.0.0
 django-heroku==0.3.1