Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Conform with new Functest test list

    It conforms with "Move testcases in the right tiers" [1].
    This patch has to be merged first to ensure the right gating in
    Functest (chicken & egg situation).

    [1] https://gerrit.opnfv.org/gerrit/#/c/66863/

    Change-Id: I13e36dc9fbc3b6fa2bae91df1af28020ebd37bbc
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index b25aad4..d96d637 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit b25aad403f6ed821053825516517040ef3988f36
+Subproject commit d96d6379d66f15cb34c95433db2922bca531bdb5