Bump djangorestframework from 3.5.0 to 3.11.2

Bumps [djangorestframework](https://github.com/encode/django-rest-framework) from 3.5.0 to 3.11.2.
- [Release notes](https://github.com/encode/django-rest-framework/releases)
- [Commits](encode/django-rest-framework@3.5.0...3.11.2)

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

Author: dependabot[bot]

requirements.txt

@@ -29,7 +29,7 @@ datapackage==0.8.1
 jsontableschema==0.10.1
 python-dateutil==2.6.1
 py4j==0.10.2.1
-djangorestframework==3.5.0
+djangorestframework==3.11.2
 djangorestframework-gis==0.11
 djangorestframework-csv==2.0.0
 pycountry==17.1.8