Update git submodules

* Update docs/submodules/container4nfv from branch 'master'
  - Merge "modify release-notes"
  - modify release-notes

    Change-Id: I7041c004ca94705e1ac8cb03b6a06a906db0be35
    Signed-off-by: Xuan Jia <jason.jiaxuan@gmail.com>

diff --git a/docs/submodules/container4nfv b/docs/submodules/container4nfv
index cdbfc1d..900e180 160000 (submodule)
--- a/docs/submodules/container4nfv
+++ b/docs/submodules/container4nfv
@@ -1 +1 @@
-Subproject commit cdbfc1d717712f330aa1412d6c59085f98b8ac5e
+Subproject commit 900e1805c2fa08dca957cb1e81c86bde0c9eb930