Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "test_kubernetes: mock file operations in test_ssh_key"
  - test_kubernetes: mock file operations in test_ssh_key

    tests take too long and we should not be createing/deleting
    files during unittests, filesystems operations introduce
    too many external issues

    Change-Id: I989c9d0a84187becdf63497c0c1ac6e10c5eac70
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 3cce3bc..0a24ca3 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 3cce3bc588bef62e980cdcee3c9b7d6eac81bed2
+Subproject commit 0a24ca320c46c10a50d38b8eab6336eb0e32f8c9