Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "Replacing references to "DefCore""
  - Replacing references to "DefCore"

    This patch removes all references to the outdated term "DefCore"
    in the Dovetail documentation. The DefCore working group has been
    renamed OpenStack InterOp Working Group some time ago.

    This patch also proposes renaming the "defcore" test area to
    "osinterop".

    JIRA: DOVETAIL-499

    Change-Id: I7bb2ca33cb1eaf17c3ca0fc79a4f923e5886ece4
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>