Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "update versions under scenario"
  - update versions under scenario

    1. post, add one or more new versions
    2. update, replace existed version as a totality
    3. delete, delete one or more versions by name
    4. in post&update, if schema is not consistent with ScenarioVersion model,
    BadRequest will be raised(only extra keys will be detected currently)
    5. in post, if project already exist, return Conflict with already exist
    message
    6. in update, if a version appears more than once, also return Conflict
    with already exist message
    7. add update with conflict unittest for projects

    Change-Id: I0d2c8a5567f3abce7b0313a64e18303af02cc002
    Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 4e72338..0889958 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 4e72338e8ac11ab69bd94a31fb27886f5f632543
+Subproject commit 0889958d6eaa4eff43df7fd4b7c34f16de41fc0b