Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Apex: Fix OS_VERSION detection"
  - Apex: Fix OS_VERSION detection

    When we run deployments for snapshot creation we typically pass in the
    OS_VERSION var so we know what openstack version we are deploying with.
    However when we run a verify/gate job to ensure that the snapshot
    deploys work we do not have this variable, and need to detect it based
    on the OPNFV branch, or if the branch is master, the deploy scenario
    naming scheme.

    Change-Id: If1445dc564d2af59b9740391de56b821b78de0b5
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 9261f36..ba6c750 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 9261f361c1ce51a8425f928895d7379fd42754c4
+Subproject commit ba6c7504201c56df6f2052cdb73c800b303447a8