Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Add a dovetail test job on huawei-pod4 to test Apex danube branch"
  - Add a dovetail test job on huawei-pod4 to test Apex danube branch

    1. Apex doesn't have danube jobs now.
    2. Dovetail is based on opnfv danube branch, so it should be tested
       against Apex danube deployment.
    3. Huawei-pod4 deployed with Apex danube (os-nosdn-nofeature-ha) and
       can be used to test.

    JIRA: DOVETAIL-494

    Change-Id: Ic3251585503c15fb416c6d9497e8acfc977ebe3e
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index fc84a25..e7d0ada 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit fc84a25aa2eae77a0a2a11659867026c55fb49a1
+Subproject commit e7d0ada29bd6acf2dab0fb79b8cbfa3b4e20fa0a