Added celery configuration module.
Added celery configuration module.

This will allow launching Celery workers via the global Celery executable,
instead of having to use `manage.py celery` (which is no longer recommended)

clever-crow-consulting/otm-core,recklessromeo/otm-core,RickMohr/otm-core,recklessromeo/otm-core,maurizi/otm-core,clever-crow-consulting/otm-core,RickMohr/otm-core,recklessromeo/otm-core,maurizi/otm-core,RickMohr/otm-core,maurizi/otm-core,clever-crow-consulting/otm-core,recklessromeo/otm-core,maurizi/otm-core,clever-crow-consulting/otm-core,RickMohr/otm-core