Better handling of DOIDbSync where DOI is not found in doi.db
Removed http call to /doi and replaced with direct Minter call

It is unclear why the DOIDbSync was calling the DoiController (http://.../doi) to add entries to the DOI.db
DoiController is not configured to update the DOI.db and does not respond to the query parameters provided - always returns 'DOI not present.'
Update Dryad 3.1 schema to not require a value for dcterms:references
Add python script for validating objects from DataONE MN API
Prepopulate dictionary
Merge branch 'dan-trello-9' into dryad-dev