* Fix graphene-django 3.x compatibility issues (thanks sjdemartini, wito-alex).
* Improve documentation (thanks sjdemartini, Plebbimon).
* Add `perform_delete` override to `DjangoDeleteMutation` (thanks calummackervoy). This allows for better soft deletes.
* Add `get_return_id` override to `DjangoBatchDeleteMutation`, enabling ID overwrites (thanks rymanso).
* Fix compatability issues with custom pks (thanks NwawelAIroume).
* Bump some package versions.
* Some general project and file clean up.
* Remove debug prints. Pardon all the mlogs.