Update git submodules

Update git submodules

* Update docs/submodules/clover from branch 'master'
  - Merge "Clover initial commit for servicemesh/route_rules, orchestration/kube_client, and tools/clover_validate_rr"
  - Clover initial commit for servicemesh/route_rules,
    orchestration/kube_client, and tools/clover_validate_rr

    Add an 'orchestration' directory. Please note that
    'orchestration' does NOT mean Clover does any orchestration ---
    similar to how Clover doesn't by itself implement tracing or
    logging, orchestration is a directory for code related to Docker
    orchestration client --- such as k8s client

    kube_client utilizes the Kubernetes python client (a dependency)
    to perform tasks against Kubernetes API server. For this commit,
    it is only tested for weighted route rule verification, it does
    three tasks:
    (1) get a list of pods under a namespace --- pod dictionary now
        only contains pod name and label dictionary: used to match
        pod name with the node name in traces from OpenTracing
    (2) check to see if a particular pod is up in a particular
        namespace: used to check if Istio pods are running in
        istio-system namespace
    (3) check if a container exists in a list of pods under a
        namespace: used to check if application pods have
        istio-proxy container running

    route_rule directly invokes istioctl as there isn't any Istio
    Python client yet.  Currently it reads and parses routerules
    from Istio, and validates if a particular trace result matches
    the routerules

    Finally, a sample tool clover_validate_rr is provided. This
    tool assumes a previous test has been ran (with an id with
    both the route-rule-under-test and corresponding traces are
    stored --- currently the assumption is tests were ran with
    redis-master running on system). The tool can be invoked:

    python clover_validate_rr.py -t <test-id> -s <service name>

    where test-id is the ID of the test (most likely uuid) and
    service name is the name of the service running in the
    Kubernetes cluster upon which test traces should be fetched
    against

    Change-Id: Ic8ab6efc23c71ac4643bee796ef986a86f6fc7dd
    Signed-off-by: Stephen Wong <stephen.kf.wong@gmail.com>