Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Make files pep8 compliant"
  - Make files pep8 compliant

    This change makes files pep8 compliant before adding the
    reuse context feature

    JIRA: YARDSTICK-886
    Change-Id: Iae7daaa159a9ddbb5809a9a7ac74f8a53683089a
    Signed-off-by: Emma Foley <emma.l.foley@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 0b9b983..56af328 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 0b9b983429994eadacedd4cdf51d63e02da31f46
+Subproject commit 56af3286c98a6c562a821f479a1a4c66262dcbab