Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Remove main() and __main__ from tests."
  - Remove main() and __main__ from tests.

    Removes the unnecessary main() functions from tests.
    Also removes shebang (#!) where it appears at the top of files.
    JIRA: YARDSTICK-861

    Change-Id: I79180d1eb9c5bce640142dd62ce28c7437c1b210
    Signed-off-by: Emma Foley <emma.l.foley@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 24a8c6d..932024f 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 24a8c6d89f150666a37a3f8daba0fce7c17a436a
+Subproject commit 932024f7d33c8915705cc857b75ce7ffbd234183