Update git submodules

Update git submodules

* Update docs/submodules/multicloud/k8s.git from branch 'master'
  to 8cdd50b6a06aef5cb0541e74a07b10bd4b01b589
  - Merge "Use httptest instead of http in unit tests"
  - Use httptest instead of http in unit tests

    Use httptest instead of http in unit tests similar to:
    https://golang.org/pkg/net/http/httptest/#example_ResponseRecorder
    Update empty body checking to account for change

    Issue-ID: MULTICLOUD-545
    Change-Id: Ib9775078c2c9ae2878b714363b569d8d79bd7698
    Signed-off-by: Kiran Kamineni <kiran.k.kamineni@intel.com>