Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Fully fix pylint warnings in test_testcase

    It partially takes into account missing-docstring.
    It is disabled for public methods as they are unit tests.

    It has been rated at 10.00/10.

    Change-Id: I70e6729b9228d58cc67a18da29b925dad22cf5bd
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 8f92a2c..c9d28a5 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 8f92a2cbfb6729f111d9e131afdbe0850ddd2e0c
+Subproject commit c9d28a538068963f6a6260a17a41e4f8c136bcfe