Operate on Multiple collections

[sgoggins]

Make it possible to spawn multiple different data collections into a single Jupyter Hub Instance.

[sgoggins]

@yuvipanda , @germonprez @scottgs : I think this is important after Omaha, but before the ACM Group Workshop. ... Integrating multiple data sets and projects is one area to think about possibly now ... but not implement until after we have a basic, single data set architecture going.