Update git submodules

* Update docs/submodules/sdnvpn from branch 'master'
  - Install run_sdnvpn_tests.py in $PATH

    It eases how Functest runs it (see testcases.yaml [1]).
    The former run_tests.py is renamed to avoid duplicated binaries (see
    [2] and [3]).

    [1] https://git.opnfv.org/functest/tree/functest/ci/testcases.yaml
    [2] https://git.opnfv.org/sfc/tree/sfc/tests/functest/run_tests.py
    [3] https://git.opnfv.org/promise/tree/promise/test/functest/run_tests.py

    Change-Id: I50219cad42bf0e085c2edf2e1abe149c2e057a99
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 9815cc6..d94269b 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 9815cc6597daa6f50a38a04579036e3eeb5c79a2
+Subproject commit d94269b2189405e854aeb6d21e476206a0b3d701