Add async functionality to backend (Django 3.0+)

[ohduran]

Description
Django now allows for async functionalities, and the project is unfortunately in need for configuration to do just that.

Possible solution
A good starting point is this article from @suda.

Alternatives
There are two options that might be on the table:
a) Just move into this configuration by default, and drop support for Django 2 and lower.
b) Cookiecutter allows for the user to decide whether to use it or not in the cookiecutter.json

Mi own preferences lean to the a) side given that a cookiecutter allows for jumpstart a new project from scratch, and it should look into the future, and not to the past.