Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Add ${DOCKER_TAG} in Docker hooks

    It eases creating Docker images based on branches or tags.

    Change-Id: Id84513c53cad72a1fcd0debf06579481609b8bc2
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 36b648a..29647ef 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 36b648a6e928ac0819a607cd2231faa803418b7a
+Subproject commit 29647efa114151d53ede5ba2d989593992c0b29f