Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Clean unit tests in "benchmark.scenarios.lib.test_create_volume.py"
  - Clean unit tests in "benchmark.scenarios.lib.test_create_volume.py

    * Use mock_object.assert_called_with instead of
        self.assertTrue(mock_object.called)
    * Remove an unneeded if clause in CreateVolume
    * Add individual tests for each method in CreateVolume

    Change-Id: I54cc56434d316f059b3822879145e6a299866fcb
    Signed-off-by: Emma Foley <emma.l.foley@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 847881b..36f0563 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 847881b9231b4a7713347e8532afdb9cae764518
+Subproject commit 36f0563490a4ee8f5b30eb7fe51a62d3b55c5b32