Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Add interface and network information to Kubernetes context

    Add to "Kubernetes" context the "interfaces" information when retrieving
    a server. This information is needed for NSPerf test cases.

    The interface information comes from the resource controller network list.
    Each replication controller will have one port per network defined.

    JIRA: YARDSTICK-1303

    Change-Id: Ifb0e17df295c042a643128c705a93876af999bad
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>