Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Replace neutron router creation with shade."
  - Replace neutron router creation with shade.

    Function create_neutron_router now uses shade client instead of neutron
    client.

    JIRA: YARDSTICK-890

    Change-Id: I819d26f4edb3af5e50f777e8ddbadf4d24820b7f
    Signed-off-by: Shobhi Jain <shobhi.jain@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index c4228f6..a854a1d 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit c4228f65829e86abadb7d93246d0b6de9dab2d51
+Subproject commit a854a1dde960b630c0c0d854dee9232e4c4e9ac8