Update git submodules

* Update docs/submodules/container4nfv from branch 'master'
  - support vagrant/libvirt

    1. add cleanup for libvirt
    2. use libvirt for deployments
    3. use yk0/ubuntu-xenial box
    4. update sleep time to reduce log size

    Change-Id: Ie1f0acc6a496180c4d73ade5f724434400fef1f7
    Signed-off-by: Guo Ruijing <ruijing.guo@intel.com>

diff --git a/docs/submodules/container4nfv b/docs/submodules/container4nfv
index cc076fe..85999db 160000 (submodule)
--- a/docs/submodules/container4nfv
+++ b/docs/submodules/container4nfv
@@ -1 +1 @@
-Subproject commit cc076fe7ba6bdc7b5298ed7b19a15cad37af0307
+Subproject commit 85999db47c5f2292968c91184021bd220c7cd246