Use test environment from the `paas-billing` repo
Use test environment from the `paas-billing` repo

Rather than trying to inject specific versions of ginkgo and godog
into the test environment, instead, employ go modules to source the
correct versions and run them.

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