Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 3f7a34a7a14c0a958a7a86a6fb5f730de365cb84
  - Refactor tag and functest_tag in Airship jjbs

    Functest hunter (functest_tag) is selected to verify Airship master
    (tag) because Airship currently deploys Ocata.

    Change-Id: I26f0971d710638688a96014d574739f482fa004c
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index e4b1426..3f7a34a 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit e4b1426a741a65834b2374c331d5a4257816bfdb
+Subproject commit 3f7a34a7a14c0a958a7a86a6fb5f730de365cb84