Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Remove Python packaging files"
  - Remove Python packaging files

    Since we don't release releng as a python project, it doesn't make much
    sense to include a setup.py.

    The jjb testenv in tox.ini is modified to pin jenkins-job-builder and no
    longer require setup.py nor jjb/test-requirements.txt, and the modules
    testenv is moved to it's own tox.ini under modules.

    Locally testing of jjb can still be done using:

      tox -e jjb

    Change-Id: I512b1a8f9cd7d48a2f14b1bbe966b525793a6fe3
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 824ebda..3aa5396 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 824ebdacf05ffba94a280c2db655e034ed567106
+Subproject commit 3aa5396e6d56712c1738754f0233d4d7b8bba40c