added Duke to the AUTHORS list
bug fix in severity handling.

Had resulted in warnings being treated like
errors.
exceptions on unrecognized nexson version numbers
removing optional meta from schema
tuples to frozensets int schema
badgerfish test
handling meta errors in badgerfish
moving toward type checking all elements in schema
the schema stuff is getting weird
tests passing with schema type checking
executable from any working dir.
better output for type errors
better message for meta type errors
study_year wrong type
better paths in messages
successfully getting id from abj in LazyAddress
v1.2 wrong meta type test
v1.2 wrong meta type test
adding type checked meta keys
cleaned up some naming