A simple database upgrade script.

This script does the following:

• A database upgrade requires the execution of numbered scripts stored in a folder. E.g. 045.createtable.sql
• There may be holes in the numbering and there isn't always a . after the number.
• The database upgrade works by looking up the current version in the database. It then compares this number to the scripts.
• If the version number from the db matches the highest number from the script then nothing is executed.
• If the number from the db is lower than the highest number from the scripts, then all scripts that contain a higher number than the db will be executed against the database.
• In addition the database version table is updated after the install with the latest number.

Install Python's MySQL adapter on your system: sudo pip install pymysql