Clean up the expiration of stale metrics and prepare for production

Clean up the expiration of stale metrics and prepare for production

 * Add power metric expiration
 * Make the map expiry keys a joined string, which will help prevent
    weird array lengths being required all over the place, makes expiry
    more generic in implementation
 * Switch routing keys to their production variants
 * _Should_ work in kubernetes as the others do, just need to deploy