Add "---" into some files of yaml

TrivialFix

Change-Id: Id2cd736f136068514f26977b434b15a8b1ffc8be

ansible/roles/glance/tasks/bootstrap_service.yml

+---
 - name: Running Glance bootstrap container
   kolla_docker:
     action: "start_container"

ansible/roles/heat/tasks/bootstrap_service.yml

+---
 - name: Running Heat bootstrap container
   kolla_docker:
     action: "start_container"

ansible/roles/ironic/tasks/bootstrap_service.yml

+---
 - name: Running Ironic bootstrap container
   kolla_docker:
     action: "start_container"

ansible/roles/kibana/tasks/pull.yml

+---
 - name: Pulling Kibana image
   kolla_docker:
     action: "pull_image"

ansible/roles/prechecks/vars/main.yml

+---
 docker_version_min: '1.10.0'
 docker_py_version_min: '1.6.0'
 ansible_version_min: '2.0.0'

docker/bifrost/bifrost-base/build_arg.yml

+---
 skip_bootstrap: true
 skip_start: true
 install_dib: true