Explore use of Alembic

[dr-rodriguez]

Alembic can be used to manage database migrations (schema updates)
https://alembic.sqlalchemy.org/en/latest/index.html

I was pointed to this as a good way to handle updating schema and we should explore it at some point. Not sure where best this would be implemented (ie, in SIMPLE, AstrodbKit, astrodb_utils, etc) but making the issue here since databases created from this template could benefit from this in place.