Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - xci: Connect releng-xci-scenarios repository

    The releng-xci scenarions have been moved to their own repository so we
    delete the copies from the releng-xci repository and also update the
    opnfv-scenario-requirements to point to the new repository.

    deploy-scenario:os-nosdn-nofeature
    installer-type:osa

    Change-Id: I1b7b3182a5e0c5b346c00b5734fd0cd3fdd5c98b
    Signed-off-by: Markos Chandras <mchandras@suse.de>