Update git submodules

* Update docs/submodules/releng from branch 'master'
  to a87ae1563709f0d1c105cc4f510e481e1e0d724a
  - Force without tty in openstack wrapper

    Else it fails when executed via Jenkins
    https://github.com/airshipit/treasuremap/blob/master/tools/openstack#L12
    https://build.opnfv.org/ci/job/airship-deploy-gate-latest/1/console

    Change-Id: Idade849b386cc4035700ba74f58450303935a08f
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 1f93df1..a87ae15 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 1f93df139b36df565a538c28ef1b0fbfe0a0f576
+Subproject commit a87ae1563709f0d1c105cc4f510e481e1e0d724a