Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Cleanup Ansible common unit tests"
  - Cleanup Ansible common unit tests

    Removed unneeded output, use proper exception checks and remove
    filesystem access.

    JIRA: YARDSTICK-1341

    Change-Id: I5c56e7b34d0e96946211e6172290bce24a156d68
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index abb0dd4..dd23339 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit abb0dd41a45dd6cbc0f1c0f2831aa2e0b4647566
+Subproject commit dd233397485e9f8c222d6d8df57cfeed207c9209