Update paas-billing release
Update paas-billing release

This commit updates pass-billing to a new version that uses the broker
plan ID to select pricing plans rather than the Cloud Foundry ID[1].
This enables pass-billing to work in multiple environments including
London and in dev.

https://github.com/alphagov/paas-billing/pull/52

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