v5.0.0

This release brings sharedb-postgres up to spec with the official ShareDB database driver test suite. More details can be found in #24 (@alecgibson)

Migration from v4

The following SQL will need to be run to migrate an existing database:

ALTER TABLE snapshots
  ALTER column doc_type
  DROP NOT NULL;

ALTER TABLE snapshots
  ALTER column data
  DROP NOT NULL;

ALTER TABLE snapshots
  ADD metadata jsonb;