Description of problem:
- Containerized uninstallation playbook does not clean up HAProxy configuration

Version-Release number of the following components:
  [root@knakayam-ose36-master1 ~]# rpm -q openshift-ansible
  openshift-ansible-3.6.173.0.48-1.git.0.1609d30.el7.noarch
  [root@knakayam-ose36-master1 ~]# rpm -q ansible
  ansible-2.3.1.0-3.el7.noarch
  [root@knakayam-ose36-master1 ~]# ansible --version
  ansible 2.3.1.0
    config file = /etc/ansible/ansible.cfg
    configured module search path = Default w/o overrides
    python version = 2.7.5 (default, Feb 11 2014, 07:46:25) [GCC 4.8.2 20140120 (Red Hat 4.8.2-13)]

How reproducible: 100%

Steps to Reproduce:

1. Install with containerized installation

  # ansible-playbook     /usr/share/ansible/openshift-ansible/playbooks/byo/config.yml

~~~
  [OSEv3:children]
  masters
  nodes
  etcd
  lb

  [OSEv3:vars]
  containerized=true

  ...
  [lb]
  knakayam-ose36-lb1.example.com
~~~

2. Uninstall cluster

  # ansible-playbook     /usr/share/ansible/openshift-ansible/playbooks/adhoc/uninstall.yml

3. Check /etc/systemd/system/haproxy.service

  #  ls /etc/systemd/system/haproxy.service

Actual results:
- /etc/systemd/system/haproxy.service remains.
- Due to this, if we re-install with "non-containerized" installation, haproxy service fails to start with following error.

  Nov 08 17:38:39 knakayam-ose36-lb1 systemd[1]: haproxy.service: main process exited, code=exited, status=1/FAILURE
  Nov 08 17:38:46 knakayam-ose36-lb1 docker[2321]: Error response from daemon: No such container: openshift_loadbalancer
  Nov 08 17:38:46 knakayam-ose36-lb1 systemd[1]: haproxy.service: control process exited, code=exited status=1
  Nov 08 17:38:46 knakayam-ose36-lb1 systemd[1]: Failed to start haproxy.service.

Expected results:
- /etc/systemd/system/haproxy.service and /etc/systemd/system/haproxy.service.d/limits.conf are removed during the uninstallation.

Additional info:
- proposal patch: https://github.com/openshift/openshift-ansible/pull/6054