No automation for changing the status of the queues

[jimdevops19]

It will be useful to create a management command to manage the status of a group of queues.
The most common scenario is to abort all the pending queues. So we can create a new file inside rqueue/management/abort_pending_queues.py directory, that will just abort the pending queues.

And this way, it could be called within the directory of the project in this way:

python manage.py abort_pending_queues