Update git submodules

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

    JIRA: RELENG-254

    Change-Id: Ia936e1ab5840b7f7acbe874bb46ca906369a4121
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 783e864..b771431 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 783e864429a09a68c361e4a65a0f602d6ab76647
+Subproject commit b771431b199906fe65c56155c9cb5d5e1a638726