Update git submodules

* Update docs/submodules/releng from branch 'master'
  to e93986f2ed9c65ca2440f35a4a35dce8fc602b71
  - Merge "Use tox as package by distribution"
  - Use tox as package by distribution

    Change-Id: Ia1d34971e1bd1c2babefa4caf3b810b3398b7187
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index fe86c2e..e93986f 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit fe86c2e9d8f77c52c2226c231964a775545a262a
+Subproject commit e93986f2ed9c65ca2440f35a4a35dce8fc602b71