Dash Ent Libraries: Universal background callbacks

Hi Nathan, I was looking into making the background callbacks easier to setup and I think we could add setup_background_callbacks on EnterpriseDash that would automatically setup everything for using background callbacks. It could use de-client to fetch info on if a redis instance is available and if not starts it and same for the celery workers instead of having them defined in the procfile it could spawn the workers on it's own if required. Basically it would do: - Check for a redis instance - If available create a background manager from the url - if not spawn the redis instance, wait for it to start and create manager from the url. - Check if celery workers are available. - if not spawn workers. Then the user would only have to do: app = EnterpriseDash() app.setup_background_callbacks() Or it could even do it by default during init.