Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Variable local_iface_name is read before it is set"
  - Variable local_iface_name is read before it is set

    Moving variable setting before reading
    Verified via TC:
    yardstick/samples/vnf_samples/nsut/ping/tc_ping_heat_context.yaml

    JIRA: YARDSTICK-899

    Change-Id: Ia2feac1ed4e67dccd02446ba27afc9d40e87be35
    Signed-off-by: Jiri Prokes <jirix.x.prokes@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 8578189..03e3d75 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 8578189f27e5560814cc78eb32757d2a20caa70a
+Subproject commit 03e3d755defe0c69a18b0ca46912cd90778a8abe