Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - fix No handler warning by calling _init_logging

    No handlers could be found for logger

    It looks like we need to call _init_logging
    to properly setup the logging during unittests.

    This should fix the influxdb unittest warning.

    JIRA: YARDSTICK-506

    Change-Id: I57f6e4088005a691d6587fc68b85455ff257a66c
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 1f5e2b8..6746ada 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 1f5e2b8f41417d38ae06af1f52cbbc123c0986e3
+Subproject commit 6746ada2e8c837da948c3260ceb8829ea1fc27de