Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - xci: Bump Kubespray SHA and sync Ansible versions

    This change
    - bumps kubespray version to 8b3ce6e418ccf48171eb5b3888ee1af84f8d71ba, taking
    Kubernetes version from 1.10.2 to 1.10.4.
    - pins Ansible version used by Kubespray to same Ansible version as the rest.
    The var kept as is in case if we need to pin Kubespray to a different Ansible
    version in future.

    installer-type:kubespray
    deploy-scenario:k8-calico-nofeature

    Change-Id: Iefbe82f0b9b10296e4362bca07630047c56630ac
    Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>