Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Add one missing res dir in refstack

    It completes "Allow overriding tempest output dir" [1]

    [1] https://gerrit.opnfv.org/gerrit/#/c/53241/

    Change-Id: I236a1eb708de324dd42440897e317ce2d0787ffc
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index bde5f1f..35a6fcd 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit bde5f1f240817737b15832b6aa555167c5396f46
+Subproject commit 35a6fcd790a173bb759499b43d25f081ed4adfed