Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 6a4f123e622a80d4a19f7428809fedb89893c1ed
  - Exclude behave tests from hunter and iruya

    For the time being, it's only part of master [1]

    [1] https://gerrit.opnfv.org/gerrit/#/c/68206/

    Change-Id: I7c8baf4bd178668c99f15029eb425e63c3a3b5a2
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index e5af792..6a4f123 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit e5af792bda666731b875ffb8a79a1cf3aabb5727
+Subproject commit 6a4f123e622a80d4a19f7428809fedb89893c1ed