Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Fix Yamllint violations for jjb/snaps"
  - Fix Yamllint violations for jjb/snaps

    JIRA: RELENG-254

    Change-Id: Ia18bb029bdb235c5e3a28bd3d0bf5f354d524769
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 443fcbc..a9ac5c3 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 443fcbc2e1adf401e303bcce67b0aa33e4b97c2d
+Subproject commit a9ac5c36a91c3e11cdbea9e45cb2300e931f6126