Occasionally grab user's history

[Kevin-Mok]

Have to opt-in and set time interval of how often to retrieve. Update User object to store last time retrieved and retrieval interval.

Substeps

• [x] make command and use cron to retrieve personal history
• [x] make options for summarized/full console logging
• [ ] modify User to store last time retrieved history and how often want history to be retrieved
• [ ] write cron job to backup listening history
  • write Django function to output desired .csv format