Require django >= 2.2 in setup.py
Require django >= 2.2 in setup.py

Signed-off-by: Mattia Rizzolo <8fbcb4197d9337a6801bce838eb7a83843b5724a@mapreri.org>

dprog-philippe-docourt/django-qr-code,dprog-philippe-docourt/django-qr-code,dprog-philippe-docourt/django-qr-code