Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "test_attacker_baremetal: don't run local commands"
  - test_attacker_baremetal: don't run local commands

    these tests were failing to mock subprocess.check_output
    and thus were trying to run sudo commands on the local
    system.

    This is dangerous.  Add the subprocess mock.

    Also mock the LOG object so we don't print
    bogus Runtime error tracebacks in the unittest logs
    when we test assertRaises()

    Change-Id: I01535f9952fbd95ce2f5972b641c51ff836e7e8c
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 0477602..93df930 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 04776024ae7a404c2987e842fe725589a56600dd
+Subproject commit 93df930fbd7e8f0f4a7868be469ab7b1fa2b3c47