Merge "Add support to OpenID Connect Authentication flow"

ansible/group_vars/all.yml

ansible/roles/haproxy-config/defaults/main.yml

ansible/roles/horizon/defaults/main.yml

ansible/roles/horizon/templates/local_settings.j2

ansible/roles/keystone/defaults/main.yml

ansible/roles/keystone/tasks/config-federation-oidc.yml

ansible/roles/keystone/tasks/config.yml

ansible/roles/keystone/tasks/deploy.yml

ansible/roles/keystone/tasks/register_identity_providers.yml

ansible/roles/keystone/templates/keystone.conf.j2

ansible/roles/keystone/templates/keystone.json.j2

ansible/roles/keystone/templates/wsgi-keystone.conf.j2

doc/source/contributor/index.rst

doc/source/contributor/setup-identity-provider.rst

doc/source/reference/shared-services/keystone-guide.rst

etc/kolla/passwords.yml

...-keystone-support-to-openid-connect-859b12492f8347fe.yaml