Currently we only need the db to keep track of the files that were
already downloaded, thus we only use one database and only one table.
A complete sql database is a bit too bulky for this purpose.
By using sqlite we can minimize and embed the db.

If an event didn't have a folder for files it was erroring.
This is fixed now by adding try-except blocks.

- limit for courses was set to low to display current courses
- unused variable docs was removed from local function

the username of my dockerhub account was misspelled

The log has options for several levels that can
be set from the command line.
The file is hardcoded as log.txt and can be toggled

- mysql creates database and tables to given mysql if not existent already
- mysql reads last change values from db
- mysql saves ch_date after downloading
- run now takes care for the variables of mysql and studip