Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Mock time.sleep() to decrease test duration"
  - Mock time.sleep() to decrease test duration

    It also returns None when getting floating ips after deleting them.
    It now runs 40 tests in 0.084s.

    Change-Id: If4b1032ab9890fd291d99beb57166ead8729d822
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 7109cd3..a6a900f 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 7109cd3916fb120ae773e8ca79ececd449525fac
+Subproject commit a6a900f1032ef0c65996a71812b62811e46b840d