Flush redis db automation

[brianavecchione]

User information in check in should not be kept for an extended period of time in order to eliminate PII. A cron job should be written to flush the redis db after a given period of time.

For Civic Hall, this means flushing the database on a daily basis after sending the necessary information to Nexudus. For an event, this may mean flushing the database after the end of the event duration. The job should be flexible to allow for personal preference depending on usage.