Multiple background, lists following, sqlalchemy integration, alembic integration

(!!!) Please don't apply this pull request before read installation instructions below

As soon as we integrated sqlalchemy deployment process a little changed.
What you need to do for deploy (except of default steps, like pip install -r requirements.txt):
1. Drop tables 'albums', 'pictures'
2. Run models creation:
    python pin/api/models/user.py
3. Edit alembic.ini in the project directory and set DB credentials, for example:
    sqlalchemy.url = postgresql://admin:111@localhost/pin
4. Run 'alembic upgrade head' from project directory

Also to remove custom lists from db please run 'pin/config/db/db_boards_cleanup.sql'
PROFIT!!!