Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "[fuel] Add Docker build jobs"
  - [fuel] Add Docker build jobs

    JIRA: FUEL-383

    Change-Id: I80049726c256d2891ae1cfbacbc54781d3d81c70
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 12aa669..a2fb2e4 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 12aa66928bd8ed576fdda6f6eeae80c6bc90c433
+Subproject commit a2fb2e42e1ffedcc3d22309ed08d9f96deb099f4