Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Include 'opnfv-pylint-verify-stream' to job list"
  - Include 'opnfv-pylint-verify-stream' to job list

    This job was not being created because it was missing from the jobs list
    in the file.

    Change-Id: Ibd66c6b654421e63f23738d6eecdca93aecf86cc
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 8a421af..6a6d5c6 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 8a421af4203f83b372152abec33056175ec66908
+Subproject commit 6a6d5c682f0bb50d29fe483eb3bdfa639b8a876c