Add orm classes

[abargar]

Adds ORM classes! Also separates out our config so we can swap in development vs. prod environment databases.

Tested:

• [x] app starts successfully
• [x] basic indicator search works
• [x] matching works

We use different schemas at the moment for the user class vs the others. I'd like to update the User class to match this one if that's cool.

Current environment variables:

DEVELOPMENT_DATABASE_URL = "sqlite:///database.db"
PRODUCTION_DATABASE_URL  = "sqlite:///database.db"
SQLLITE_DB_PATH = './database.db'