Add mongodb s3_bucket config to Carrenza/hieradata
Add mongodb s3_bucket config to Carrenza/hieradata

- The CI-licensify mongo backup to s3 fails because these bucket names
  are not defined in the non-AWS environment hieradata

- This change will re-enable the backups which have not run in half a
  year.

- This answers a ticket from 2nd-line
  (https://govuk.zendesk.com/agent/tickets/2820116)

Solo @schmie

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet