Update .gitlab-ci.yml to start building ansible 2.8
Update .gitlab-ci.yml to start building ansible 2.8, as this supports docker_stack deployment. See https://docs.ansible.com/ansible/devel/modules/docker_stack_module.html
Update .gitlab-ci.yml to start building ansible 2.8, as this supports docker_stack deployment. See https://docs.ansible.com/ansible/devel/modules/docker_stack_module.html