Bump Ansible to 2.6.x

Bump the maximum supported version of Ansible to 2.6.x for both Kayobe
and Kolla Ansible.

Change-Id: Ia8691d127bb6ce57dcd6fdac25f0357844f5cbaa
Story: 2004287
Task: 27839

ansible/roles/kolla-ansible/templates/requirements.txt.j2

@@ -7,7 +7,7 @@ kolla-ansible=={{ kolla_openstack_release }}
 {% endif %}
 # Limit the version of ansible used by kolla-ansible to avoid new releases from
 # breaking tested code. Changes to this limit should be tested.
-ansible<2.6
+ansible<2.7
 {% if kolla_ansible_venv_extra_requirements is defined %}
 {% for item in kolla_ansible_venv_extra_requirements %}
 {{ item }}

requirements.txt

@@ -7,7 +7,7 @@ pbr>=2.0 # Apache-2.0
 # with the fix backported. It can be installed by uncommenting the following
 # line and commenting the one after.
 # -e git+https://github.com/stackhpc/ansible@issue-30350-2.3#egg=ansible-issue-30350-2.3 # GPLv3
-ansible>=2.4.0,<2.6.0 # GPLv3
+ansible>=2.4.0,<2.7.0 # GPLv3
 cliff>=2.5.0 # Apache
 netaddr!=0.7.16,>=0.7.13 # BSD
 PyYAML>=3.10.0 # MIT