declare private resources as private

REFERENCE.md

manifests/cli.pp

manifests/config/admin.pp

manifests/config/option.pp

manifests/core.pp

manifests/core/config.pp

manifests/core/install.pp

manifests/core/update.pp

manifests/external_fact.pp

manifests/resource.pp

manifests/resource/activate.pp

manifests/resource/install.pp

manifests/resource/uninstall.pp

manifests/resource/update.pp

manifests/site.pp

spec/classes/cli_spec.rb

spec/classes/core_spec.rb

spec/classes/external_fact_spec.rb

spec/classes/resource_spec.rb

spec/classes/site_spec.rb