Update git submodules

* Update docs/submodules/container4nfv from branch 'master'
  - update opnfv/containter box

    1. add flannel, calico, busybox, nginx and ubuntu in box,
    2. use whole file instead of patch
    3. deploy new box

    Change-Id: I937e0df264ff7b639b4d6e8b7199f9502e502340
    Signed-off-by: Guo Ruijing <ruijing.guo@intel.com>

diff --git a/docs/submodules/container4nfv b/docs/submodules/container4nfv
index 39730e3..b2da960 160000 (submodule)
--- a/docs/submodules/container4nfv
+++ b/docs/submodules/container4nfv
@@ -1 +1 @@
-Subproject commit 39730e33e9e020930990e4f9d23128df25a2c94c
+Subproject commit b2da960212571fc3e287eedcdc4c8c92fed9bf83