Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Update documentation of Functest"
  - Update documentation of Functest

    Mainly update the robotframework part, according to this patch:
    https://gerrit.opnfv.org/gerrit/#/c/47841/

    Change-Id: If4dee6233ba65dd83734e0465d0dc6e8d5753da3
    Signed-off-by: Linda Wang <wangwulin@huawei.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 06ab9f1..e63b856 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 06ab9f1aaed50a5c78f3ed10f56cac8cdb2c75c7
+Subproject commit e63b856182cb65f1943f83b672e7d9e8b9f3dc3e