Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Create Gambia Jobs for Yardstick 1/2

    Add Gambia jobs for Yardstick gate:
    - yardstick-verify-gambia
    - yardstick-merge-gambia
    Keep fraser jobs until Gambia 7.0.0 is released.

    Gambia jobs for Yardstick daily will be added in next patch.

    Change-Id: Id02bcb8197dd1f6d0b8f5baddef684a97e269a14
    Signed-off-by: jenkins-ci <jenkins-opnfv-ci@opnfv.org>
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>
    Signed-off-by: rexlee8776 <limingjiang@huawei.com>
    Signed-off-by: Patrice Buriez <patrice.buriez@intel.com>