allow scoring functions to accept an optional hub connection

[nickreich]

If specified, the hub connection object could provide a way to validate that all required quantiles for specific output_type_ids are present. And if not, the user should be warned.

Perhaps some of these functions exist in hubValidations already?

[elray1]

Do we need this in this package? I think I would be comfortable saying that validations that all required quantiles are present should be done at time of submission to a hub or as part of some other process for validating model output files outside of the context of scoring.