Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Revert "Bugfix: ansible version should be the same both in Dockerfile and requirements.txt""
  - Revert "Bugfix: ansible version should be the same both in Dockerfile and requirements.txt"

    This reverts commit 662de49b9f6c116d15882aed9e678cd3cf67494b.

    JIRA: YARDSTICK-1411

    Change-Id: Id277aa8711c9ff77e085d26c90546eecc3490535
    Signed-off-by: rexlee8776 <limingjiang@huawei.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index ea35545..8dcd0b8 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit ea355452bca9ae9939f63c0c0b94f4fbf5c3619a
+Subproject commit 8dcd0b89eee6e4bbc69ae0d6f4673a0fdd8ee4bf