Log Message:
py-django-admin-sortable2: updated to 1.0

1.0
Added support for Django 3.2
Drop support for Python-2.7, 3.4 and 3.5.
Drop support for Django-1.10, 1.11, 2.0 and 2.1.
Add Python-3.9 to the testing matrix.
Refactor code base to clean Python-3 syntax.