WIP: Esap gateway zooniverse

Implement several changes that are required to provide data discovery access to the Zooniverse Panoptes database. Implemented preliminary test cases to discover Zooniverse Projects and Workflows for a particular Zooniverse user.

Highlights include:

• Support for the react-json-schema uiSchema component.
• Option for persistent service connector instance between construct_query and run_query.

Outstanding issues include how to do proper database migration.