py-flower: update to 1.0.0.

Changes not found. But note:

Important

Please note that from version 1.0.1 Flower uses Celery 5 and has
to be invoked in the same style as celery commands do.

The key takeaway here is that the Celery app's arguments have to
be specified after the celery command and Flower's arguments have
to be specified after the flower sub-command.

This is the template to follow:

celery [celery args] flower [flower args]

(wiz)