Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - ansible: update package proxy code

    re-enable retries

    Change-Id: I77738250e8aa8de3c8a8a1019093af04ce785ae0
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 3e29adb..478e2b8 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 3e29adbe7bf52519fbcc86012e2fdafc89d4bbe4
+Subproject commit 478e2b801ca2e0e6e47f7e7dcf80b9b6e5b8beba