Update git submodules

* Update docs/submodules/releng from branch 'master'
  to c5077b9384624acd51f65c394ff930d71d01f8a5
  - Switch to ubuntu when deploying Airship

    Change-Id: I1bb9da34dd860995cf1308014880eda4a6c3a01c
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 3f7a34a..c5077b9 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 3f7a34a7a14c0a958a7a86a6fb5f730de365cb84
+Subproject commit c5077b9384624acd51f65c394ff930d71d01f8a5