Enable package gating

Example taken from https://docs.fedoraproject.org/en-US/ci/gating/#_enable
+ comments in https://src.fedoraproject.org/rpms/python-virtualenv/pull-request/10

gating.yaml

@@ -0,0 +1,7 @@
+--- !Policy
+product_versions:
+  - fedora-*
+decision_context: bodhi_update_push_stable
+subject_type: koji_build
+rules:
+  - !PassingTestCaseRule {test_case_name: org.centos.prod.ci.pipeline.allpackages-build.package.test.functional.complete}