Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Add traffic duration support in test case"
  - Add traffic duration support in test case

    Implement code to support traffic_duration field in test case options.
    This updates the 'duration' in Landslide session profile.
    traffic_duration should always be much less than runner duration/timeout.

    JIRA: YARDSTICK-1427

    Change-Id: I51094bade683ca8758136ccb619e8894a2ecef72
    Signed-off-by: Orest Voznyy <orestx.voznyy@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index e0c6f7f..07a2b7a 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit e0c6f7f40d4640210fe1ad41ef40dfcdcef5f463
+Subproject commit 07a2b7a1c87469f4efe2bcd9c3b39015e53afe44