Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Cleanup OpenStack utils test cases"
  - Cleanup OpenStack utils test cases

    Remove logging console output during test execution.

    JIRA: YARDSTICK-1230

    Change-Id: I1b61f0f18bfb6e5a63c9027537cfb736261c4926
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 2d10b0b..bbced56 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 2d10b0bf7238f5417d46f89c76b856f7e345f738
+Subproject commit bbced563ad9ceca5021c65a2e6284861d36db4f8