Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge changes from topics 'YARDSTICK-1343', 'YARDSTICK-1342'

    * changes:
      Cleanup EnvironmentTestCase unit tests
      Cleanup Testcase unit tests

  - Cleanup EnvironmentTestCase unit tests

    Removed unneeded output.

    JIRA: YARDSTICK-1343

    Change-Id: Ifad21a62ce1152976952a4b8c5a142fa5a544904
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>
  - Cleanup Testcase unit tests

    Removed unneeded output.

    JIRA: YARDSTICK-1342

    Change-Id: I45ab14f854cd059625c1a96959b1cbd0a19f52a8
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index dd23339..e71d784 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit dd233397485e9f8c222d6d8df57cfeed207c9209
+Subproject commit e71d784db91d3f13c6c9f26d7ec13b9b7b8dd194