New script to sync mailman lists and mysql queries

- In the table 'updating_mail_lists', store mailman lists and their respective
  mysql queries.
- When the script (update_mail.py) is run, all mailman lists are syncronized
  with their respective mysql query. That is, if list '2016' queries all
  ruddock members in the class of 2016, then the script will add/remove anyone
  according to the mysql query.
- If the script has an error, then an email with details is sent to imss@ruddock
- If the mysql query has no results, then an email is sent to imss@ruddock
- Once the script is finalized, it should be run every day or so in a cron job.
- Be sure that each list in 'updating_mail_lists' is set up with correct
  permissions. This means that it should not allow user addition/deletion, and
  should describe in the footer how users can unsubscribe (via the ruddock
  website). Additionally, Users should be automatically approved if added
  via the script.