Merge branch 'set-build-token-CN' into 'master'

Add the CI Job trigger as the build trigger

Closes charts/gitlab#586

See merge request gitlab-org/gitlab-ce!20619

.gitlab-ci.yml

@@ -327,7 +327,7 @@ cloud-native-image:
   cache: {}
   script:
     - gem install gitlab --no-ri --no-rdoc
-    - ./scripts/trigger-build cng
+    - BUILD_TRIGGER_TOKEN=$CI_JOB_TOKEN scripts/trigger-build cng
   only:
     - tags@gitlab-org/gitlab-ce
     - tags@gitlab-org/gitlab-ee