Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Use computes + control for NUM_OS_SYSTEM

    This is not going to work when we want to make our HA
    CSIT work, since I think Apex will be having 3
    openstack control nodes, and our CSIT won't know what
    to do with '5' (3 control + 2 compute) openstack
    nodes. But, we can cross that bridge when we get
    there.

    Change-Id: I9c74b2ec73e5af0039d93f9ed812fc3c100a3e4a
    Signed-off-by: Jamo Luhrsen <jluhrsen@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 3a641fc..5c8fa33 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 3a641fcd1e3e844f134245d212886a062c79ff77
+Subproject commit 5c8fa3362658be5e8f8551704065fe3a18dbcc60