Update git submodules

* Update docs/submodules/releng from branch 'master'
  to a20c256e92007e5fe667b8b88e24d40a8e1e5795
  - [fuel] stable/iruya branch

    Signed-off-by: Cristina Pauna <cristina.pauna@enea.com>
    Change-Id: I37b0fcb36abc70e0b92f36f62e345ec56e57ca0d

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 848084f..a20c256 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 848084f7aeb9422dab76de9953da6c9898aa9c39
+Subproject commit a20c256e92007e5fe667b8b88e24d40a8e1e5795