Add site production status

This adds a 'production status' to sites.  Possible statuses include:

- `PRODUCTION` for sites that are in finished and in production
- `DEVELOPMENT` for sites that are currently under development
- `ARCHIVED` for sites that are kept around for purely archival reasons

Production sites will be scanned at least once every 14 days and development sites will be scanned every 31 days.
fixed in https://github.com/mfairchild365/site_master/commit/dd858bcb06f91c9b2328b03a184b9adbef4eaf90