Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Create Stable Branch Jobs for container4nfv"
  - Create Stable Branch Jobs for container4nfv

    Change-Id: Icc0999a5f9dcb2052dc34e21c8de754e9aec0909
    Signed-off-by: jenkins-ci <jenkins-opnfv-ci@opnfv.org>
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 1a8ff50..9e42ba2 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 1a8ff508b48204ae581c5f20fa8b3ef64c3579a8
+Subproject commit 9e42ba29898647aa31b6687a5ca0bac5b2707510