Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Update Functest documentation for Euphrates"
  - Update Functest documentation for Euphrates

    - Better description of Alpine docker (default artifact)
    - Reorganization of config and user guide
    - Upgrade of the developer guide

    Change-Id: Ie8e10f027bfcdb01c992cd161a1af2d6d6e29536
    Signed-off-by: Morgan Richomme <morgan.richomme@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 405a087..843fbe9 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 405a0872282f5b29bb9e60ba19b11b17c8047647
+Subproject commit 843fbe920471eff37f7acccb4f56bd603bfe22ba