Stringify graphite metric thresholds in icinga::graphite
Stringify graphite metric thresholds in icinga::graphite

These values can sometimes be plain numbers. Matching them with a regex leads
to failures under the future parser. Stringify them so that regex matching can
operate correctly and stop puppet-lint complaining about how we do it.

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