Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - kubernetes_utils: avoid 404 error code in delete_config_map()

    JIRA: YARDSTICK-1318

    Change-Id: I0c04bd2928d5a4166b483f0c4f9f75fa9e5e00d2
    Signed-off-by: Mytnyk, Volodymyr <volodymyrx.mytnyk@intel.com>
  - kubernetes_utils: avoid 404 error code in delete_replication_controller()

    JIRA: YARDSTICK-1319

    Change-Id: I8370c5ef4e43e58a8bb9c3aac60a089b0981dda0
    Signed-off-by: Mytnyk, Volodymyr <volodymyrx.mytnyk@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 305b69c..bc9601b 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 305b69cc6b840ced701a09bca0435937dcb42723
+Subproject commit bc9601ba236447ea3003411e2a7f705545759340