Pre-create db folder for users

[mikeckennedy]

Some users are reporting this error because they have not created the db folder first. Not sure whether this was missed or just not emphasized enough in the course but it's no big deal to create that folder in the starter code to help smooth things over:

sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) unable to open database file
(Background on this error at: (link: http://sqlalche.me/e/e3q8) sqlalche.me/e/e3q8)

During Lesson 09 > Creating tables.

Could be an issue on my end, but the only way I found to make it work is to create the db folder myself.