Bump min Ansible version to 2.2.0

Different Y stream version in Ansible is not compatible. Since ansible
2.2.0 is released for a while. It is time for kolla-ansible to bump the
min Ansible version. Then we can remove the annoying WARNING message
in deploying logs and use the new features.

Change-Id: I99f3c5678f6d2d1f93d61c660fbd166184ff6422