Investigate Alembic

[chrisburr]

https://alembic.sqlalchemy.org/en/latest/

[chaen]

Conclusion from the Dirac-Rucio workshop:

• Alembic is good and did not fail
• For oracle, it requires special karma to run, so Atlas generates the SQL by Alembic and run it by hand
• One file per change (skeleton from Alembic)
• We should consider running it as a pre-upgrade hook (Atlas does not, because of Oracle)