Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Create a tox env to check yaml files

    It also fixes all testcases config files.

    Change-Id: I81a6ffb8b7acf4239c79129dc842e283d3d32b35
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 462b1f7..90b8e79 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 462b1f77176092d2ea075f32bf60d06920c87240
+Subproject commit 90b8e7922a42defb3e571a0a8e81306e9abc0fe3