Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "A new docker container for QTIP"
  - A new docker container for QTIP

    This docker container can provide networking test service.
    Build this docker image by using opnfv docker build job.

    JIRA: QTIP-293

    Change-Id: I12310138a7c0b7b15bf5d34fb56bbbec1e65d206
    Signed-off-by: zhihui wu <wu.zhihui1@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index fe82048..2d6a66e 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit fe8204895e7bf673e453f367be3c5e6a54a0716d
+Subproject commit 2d6a66e59494e764b133768245b4ed8b9e4db14c