Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Assign yardstick/barometer to ericsson-build4"
  - Assign yardstick/barometer to ericsson-build4

    This is a temporary fix until we can determine the full list of
    requirements from each project needed for the opnfv-build-ubuntu labled
    servers.

    Previously these were building fine on ericsson-build4, so reassigning
    them there should keep there builds green.

    Change-Id: I767b6faa718cd6dd4b9fd17f83e7ee817cfb8c4d
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>