Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Disable functest-kubernetes master gates

    Our master containers can't be verify vs k8s 1.13 any longer [1].
    We do multiply SUT to verify all Functest kubernetes branches.

    [1] https://build.opnfv.org/ci/view/functest-kubernetes/

    Change-Id: Icb8c65d74d9739c38bc9b24de8c66ad46b40cc2f
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index fec1da8..25a313f 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit fec1da85bea695e5e23464841762cd1a78c8718e
+Subproject commit 25a313f538e5fb1fcd8a3203c75d744ef07f074d