Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Automatically download defcore.txt

    It stops writing files in Functest package dirs and cleans instance
    variables in refstack modules too.

    Change-Id: Iaddbe4fbaf12d1af207b86d4e44258efdc6d6f3a
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 02bd6e3..a1b0f64 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 02bd6e30668b477781ab007e82bfe2a207baa8b7
+Subproject commit a1b0f64bccea682e55ec5086aef979df57cf686f