Drop cf_exporer filter for Buildpacks
Drop cf_exporer filter for Buildpacks

The "Buildpacks" collector filter is not supported in cf_exporter v0.8.0. It is
added in v0.10.0.

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