Update git submodules

* Update docs/submodules/stor4nfv from branch 'master'
  - Merge "Local Documentation Builds"
  - Local Documentation Builds

        This adds configuration for performing local documentation builds
        with the following simple command:

        tox -e docs

    Change-Id: I68d939d6b1c7e27fc5d266d0934e355560ee7748
    Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>

diff --git a/docs/submodules/stor4nfv b/docs/submodules/stor4nfv
index 6b637d1..cefd1d0 160000 (submodule)
--- a/docs/submodules/stor4nfv
+++ b/docs/submodules/stor4nfv
@@ -1 +1 @@
-Subproject commit 6b637d11c99450ed0a1f3b9a5231ccea82e5cd5b
+Subproject commit cefd1d0854ee948acc7147834146914983a11556