Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Fix 1 typo in dockerslicing.md

    Change-Id: I0bb4c46d3b554cca1dfcaafbf564d9871957c346
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index a3123a3..55d1287 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit a3123a3e72a8ab81814420a67db60b2397525989
+Subproject commit 55d1287585fac93d05e9da5aae8cd1f23a372f1d