Comment 5 for bug 1690688

The celery update requires (so far) the following changes:

 - uupdate of src:celery itself, along with refreshing of patches and dependencies.
 - patch to src:sphinx-celery to build python2 and python3 binary packages [will also send to Debian]
 - uupdate of src:billiard as a versioned requirement of the new celery
 - building against the version of kombu in artful-proposed

There may be more changes needed, but wanted to publicize this is where I'm at so far.