Update git submodules

* Update docs/submodules/functest from branch 'stable/euphrates'
  - Include tempest_custom in the documentation

    Change-Id: I86300fff399d1bc73eeeed76b5057e3f6d2f85f3
    Signed-off-by: Jose Lausuch <jalausuch@suse.com>
    (cherry picked from commit 832bb86db4fba9f65aebf09c058592d28e418134)

diff --git a/docs/submodules/functest b/docs/submodules/functest
index bee66e3..e7a7c7e 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit bee66e3dbb7116eab1f5b7485eff9d0e291089d6
+Subproject commit e7a7c7ec03880f42411efd9e6703b16930b2372d