Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  to fb8006581900910bb77eae9fa0a852b853a30a4a
  - Deploy Airship on POD10

    Lots of fixes have been merged vs POD10 recently:
    https://gerrit.opnfv.org/gerrit/c/airship/+/68872
    https://gerrit.opnfv.org/gerrit/c/airship/+/68942
    https://gerrit.opnfv.org/gerrit/c/releng/+/68955
    https://gerrit.opnfv.org/gerrit/c/airship/+/68957

    Nothig seems currently deployed then we can try a deployment.

    Change-Id: I4c461973f3b9a06e75b76980965fa0e741a0909b
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>