---
upgrade:
  - The following drivers are removed due to the lack of maintainers
    of the drivers ``CiscoCsrIPsecDriver``, ``FedoraStrongSwanDriver``,
    ``VyattaIPsecDriver``. Please refer the following `mailing list post
    <http://lists.openstack.org/pipermail/openstack-dev/2018-February/127793.html>`_
    for more detail.