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* Update docs/submodules/yardstick from branch 'master'
  - Merge "Add new Kubernetes resource kind: "CustomResourceDefinition""
  - Add new Kubernetes resource kind: "CustomResourceDefinition"

    Custom resource definition example in Kubernetes:
      apiVersion: "apiextensions.k8s.io/v1beta"
      kind: CustomResourceDefinition
      metadata:
        name: networks.kubernetes.com
      spec:
        group: kubernetes.com
        version: v1
        scope: Namespaced
        names:
          plural: networks
          singular: network
          kind: Network

    Proposed Kubernetes context network definition:
      context:
        custom_resources:
          - name: network        # name of the resource (singular)
            version: v1          # optional, "v1" by default
            scope: Namespaced    # optional, "Namespaced" by default

    From this definition, we will extract the Kubernetes parameters:
      - metadata.name: custom_resources.name + "s" + context_name + ".com"
      - spec.group: context_name + ".com"
      - spec.scope: custom_resources.scope
      - spec.version: custom_resources.version
      - spec.names.plural: custom_resources.name + "s"
      - spec.names.singular: custom_resources.name
      - spec.names.kind: custom_resources.name with first capital letter

    [1] https://kubernetes.io/docs/concepts/api-extension/custom-resources/

    JIRA: YARDSTICK-1163

    Change-Id: If8980dc3f6ddf9c6949bf15be8011aa98482ddc9
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>