According to their compatibility matrix[1] the 1.11.5 version seems to be deprecated. This change updates the CentOS repository reference. [1] https://github.com/cri-o/cri-o#compatibility-matrix-cri-o---kubernetes-clusters
* Fix bootstrap_os/ubuntu idempotency * Update bastion role * move container_engine in sub-roles * requires ansible 2.5 * ubuntu18 as first CI job