Add Alembic Modules to Enable Upgrades

Revision as of 2015-Aug-24:
The following are Neutron alembic files that could be good examples I think:
- This alembic file does a time-zero bootstrap of the database: https://github.com/openstack/neutron/blob/master/neutron/db/migration/alembic_migrations/versions/juno_initial.py
(Not that the icehouse bootstrap is not available, I believe because we only support one year of releases)
- This alembic is the kilo milestone alembic file:
https://github.com/openstack/neutron/blob/master/neutron/db/migration/alembic_migrations/versions/kilo_release.py

Barbican uses Alembic to enable controlled modification of the database schema. However, Barbican is missing some Alembic version modules as compared to other OpenStack projects that use Alembic, such as Neutron and Sahara. In particular, Barbican should have a time-zero base script that creates all tables within the system (eg. https://github.com/openstack/sahara/blob/master/sahara/db/migration/alembic_migrations/versions/001_icehouse.py), and then Barbican should insert version modules that represent the schema at a final release (eg. https://github.com/openstack/neutron/blob/master/neutron/db/migration/alembic_migrations/versions/icehouse_release.py). It would probably be sufficient to use Juno as the initial base line version as Barbican is not yet out of incubation. There should be no reason to compress or remove version files as long as the release version modules are inserted as per the example above. Once this effort is completed, running 'bin/barbican-db-manage.py --dburl http://www.anyhostnamehere.com history' should reveal the sequence of the Alembic version modules, with the base pointing to the juno_release.py version, with all other version files sequentially listed/dependent after that.