Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Clean test-requirements.txt"
  - Clean test-requirements.txt

    Now only the mandatory requirements related to unit testing are listed
    in test-requirements.txt.

    Change-Id: I2f17a9e18e90d779ddc80b1ace9ac770a76c3385
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 8e6892b..59d4e97 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 8e6892b8fd6a2e28915c903baf1544c455dc881a
+Subproject commit 59d4e9757e52f452a67bbce48c2ebafc431f4cb1