Added Flask-Migrate - Closes #64
Removed default calendar from user object
using Flask-Migrates env file
removed old attribute from User model
Integrated Flask-Migrate into Longboxed. No longer need to user Alembic directly.

Merge branch 'feature/migrations' into develop
Added config dictionary to settings.py
added init_app methods to all configurations.
added stores to configuration classes
changed configuration method in the factory methods
removed imports
store object is now generated by configuration files
updated manager and wsgi to support the new configuration changes
moved migrate extension into the manage.py module. gave 'Shell' command model contexts
Config classes now have init_app() method and ability to return relevant datastore for images

Merge branch 'feature/configuration' into develop