Update git submodules

* Update docs/submodules/functest from branch 'stable/euphrates'
  - Fix the doc of snaps test

    snaps_health_check does not allocate a floating ip to the vm,
    but a fixed ip instead.

    Change-Id: Ia43885993135dec56aba08b0e157ac2c9f715e06
    Signed-off-by: Linda Wang <wangwulin@huawei.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index f962e5d..c0aa53c 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit f962e5dd6a92f371c9a829972041f9afb1cb5314
+Subproject commit c0aa53c61fdee02bc880a962b9a3de34411ec8eb