Added the SQLALCHEMY_DATABASE_URI setting

This setting is for configuring the SQLAchemy database URI.
Carefully importing the SQLAlchemy Flask extension
Changed the module structure around, a bit.
Started some dummy templates just to work with
Started a blueprint for user management
Provide a canonical path to app.config.from_pyfile

Without it, the assumption gets made that the name of the provided .py
file is in the same directory as the "bourbon" module.
Added some DB models to the "page" blueprint
Added a default route for "/"
Renamed all references of "[Bb]ourbon" to "[Cc]ask".