Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "Introduce the Barbican in XCI for SFC-HA scenario"
  - Introduce the Barbican in XCI for SFC-HA scenario

    The barbican OS component is introduced for SFC HA deployed scenario.
    The reason behind is that In HA scenarios we need Openstack Barbican to
    gather and store the fernet keys so Tacker can access them and be able to
    register new VIMs.

    deploy-scenario:os-odl-sfc
    installer-type:osa

    JIRA: SFC-131

    Change-Id: Ife416fb2a7dc04ddadc93f962695aee4ed448501
    Signed-off-by: Panagiotis Karalis <pkaralis@intracom-telecom.com>