Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 99e573472d7085541cc5c01da1b02dfec2f4fa21
  - Run tests in parallel

    Change-Id: I1e946aa9f51fe86a3f351f56ad389262be6c8b1f
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index e3d6d69..99e5734 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit e3d6d69ace413104475c38e56c5bb4eb70caf786
+Subproject commit 99e573472d7085541cc5c01da1b02dfec2f4fa21