title: Alembic Migrations without Database
body: <p>Is it possible to have Alembic <a href="https://alembic.readthedocs.org/en/latest/autogenerate.html" rel="noreferrer">auto-generate migrations</a> without it having access to the database? </p>
  
  <p>For example django / south are able to do this by <a href="https://docs.djangoproject.com/en/1.9/topics/migrations/#migration-files" rel="noreferrer">comparing the current version of a <code>Model</code> against a previous snapshot of the <code>Model</code></a>.</p>