Prod release

[snim2]

• Set CACHEOPS_DEGRADE_ON_FAILURE to True

Testing

• List env vars for staging dalmatian service list-environment-variables -i nhsx-website -s web -e staging
• Set REDIS_HOST to something incorrect
• Restart the containers dalmatian service restart-containers -s web -e staging -i nhsx-website
• Keep Papertrail open and watch for errors like RuntimeWarning: The cacheops cache is unreachable!
• Check that the site is still running
• Set the REDIS_HOST back to it's previous value
• Restart the containers again