Generate real Swagger/OpenAPI 2.0 specifications from a Django Rest
Framework API.

Features:

- full support for nested serializers and schemas
- response schemas and descriptions
- model definitions compatible with codegen tools
- customization hooks at all points in the spec generation process
- JSON and YAML format for spec
- bundles latest version of swagger-ui and redoc for viewing the generated
  documentation
- schema view is cacheable out of the box
- generated Swagger schema can be automatically validated by
  swagger-spec-validator or flex
- supports Django REST Framework API versioning with URLPathVersioning
  and NamespaceVersioning (other DRF or custom versioning schemes are
  not currently supported)
