Bump paas-billing from v0.58.0 to v0.59.0
Bump paas-billing from v0.58.0 to v0.59.0

Full diff: https://github.com/alphagov/paas-billing/compare/v0.58.0...v0.59.0

Just the one PR - alphagov/paas-billing#66 ([#164493738] Billable events are already in GBP)

alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf