Add new Kubernetes resource kind: "Network"

Add new Kubernetes resource kind: "Network"

Add a new Kubernetes resource kind: "Network" [1] [2]
Kubernetes network plugins (alpha definition): [3]

Network definition example in Kubernetes:
  apiVersion: "kubernetes.com/v1"
  kind: Network
  metadata:
    name: flannel
  plugin: flannel
  args: '[
    {delegate": {"isDefaultGateway": true}}
  ]'

Proposed Kubernetes context network definition:
  context:
    networks:
      - name: flannel
        plugin: flannel
        args: (string)
      - name: sriov_upload
        plugin: sriov
        args: (string)

[1]https://builders.intel.com/docs/networkbuilders/multiple-network-interfaces-in-kubernetes-application-note.pdf
[2]http://cdn.opensourcecloud.cn/zt/k8s/01.pdf
[3]https://kubernetes.io/docs/concepts/cluster-administration/network-plugins/

JIRA: YARDSTICK-1160

Change-Id: I71a49ac14e3d28ded91d2ed3cd9cc527e40303f7
Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>