v2.0.0 - Set current_version attribute to postgresql datastore - Add support for indexing from head releases - Replace RevisionMetadataIndexer with DirectoryMetadataIndexer - Add support for running the server with 'postgresql' storage cls - tests: Shorten definition of REVISION - tests: Simplify definition of ORIGINS list - tests: use stock pytest_postgresql factory function - Rewrite origin_head.py as a normal function instead of an indexer - Convert test_origin_head from unittest to pytest