One notify in tacker is not correct

[zhongshengping]

There is a notify "Restart tacker containers" in `roles/tacker/tasks/config.yml`:

```

- name: Copying over existing policy.json
  template:
    src: "{{ node_custom_config }}/tacker/policy.json"
    dest: "{{ node_config_directory }}/{{ item.key }}/policy.json"
  register: tacker_policy_jsons
  when:
    - inventory_hostname in groups[item.value.group]
    - item.value.enabled | bool
    - tacker_policy.stat.exists
  with_dict: "{{ tacker_services }}"
  notify:
    - Restart tacker containers

```

But no handler named "Restart tacker containers" is defined, so when user use a custom policy file for tacker, the deployment will be failed.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/476807

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/476807
Committed: https://git.openstack.org/cgit/openstack/kolla-ansible/commit/?id=acecdc2cf1506811f41c53860a3ff3c673370e9a
Submitter: Jenkins
Branch: master

commit acecdc2cf1506811f41c53860a3ff3c673370e9a
Author: ZhongShengping <[e-mail]>
Date: Fri Jun 23 15:23:52 2017 +0800

    The notify "Restart tacker containers" is not correct

    No handler named "Restart tacker containers", and we should restart
    the tacker container according to the context

    Change-Id: Idad8843e85eeb536d7abf8332606801f5b6e78ce
    Closes-Bug: #1700007

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/kolla-ansible 5.0.0.0b3 development milestone.