Update git submodules

Update git submodules

* Update docs/submodules/apex from branch 'stable/euphrates'
  - Improves clean to cleanup virsh nets and and other bridges

    Currently only the admin and external bridges will be removed from the
    jumphost which is only really clean for a baremetal deployment.  Virtual
    deployments will leave br-tenant, br-api, br-storage.  This patch
    removes those as well as deletes all Apex virsh networks from libvirt.

    Also checks if authorized_keys exists before trying to edit it.

    Change-Id: I1affe2733ba1dc38fd3b91fb14398454137f00a4
    Signed-off-by: Tim Rozet <trozet@redhat.com>
    (cherry picked from commit 02dc854a504569da15b0e41353a9f456e02599ad)