The record() program and cli is not yet working. For that we need a
working `FSDiff` next. Then we'll finally be ready to start recording
file information.
This is meant to hold schemas and migrations. It contains an
`__init__.py` due to a limitation of `importlib.resources` outlined in
detail here: https://github.com/python/importlib_resources/issues/58
Eventually the schema submodule will handle automatic migration of older
databases when importing into new stores.
