Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Change "KubernetesObject" class name to "ReplicationController""
  - Change "KubernetesObject" class name to "ReplicationController"

    The class name "KubernetesObject" is not accurate. This class holds
    the definition of a Kubernetes replication controller. The suggested name
    is therefore "ReplicationControllerObject".

    JIRA: YARDSTICK-1180

    Change-Id: I9ee9228f9528cb779e54a9bc178760b6e24c85c2
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>