Put workshop hub's users on datahub's pool
Put workshop hub's users on datahub's pool

We don't want the big datahub image to be present on any
nodes it doesn't need to be in. If we don't limit this, the
hook pre-puller will pull this image in all nodes - we do
not want that.

ryanlovett/datahub,berkeley-dsep-infra/datahub,ryanlovett/datahub,ryanlovett/datahub,berkeley-dsep-infra/datahub,berkeley-dsep-infra/datahub