Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "refstack client: improvement and fix of TestCase usage"
  - refstack client: improvement and fix of TestCase usage

    JIRA: FUNCTEST-772

    1, RefstackClientParser should not be a subclass of TestCase
    2, tempest_conf.py used for generating reference tempest.conf file
       not related to functest cmd, use logger is enough

    Change-Id: If9c37331a5a7687e5704e546efcdea8175b1529c
    Signed-off-by: MatthewLi <matthew.lijun@huawei.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 881edc3..2bd6e7d 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 881edc3942e42ccd9088ed9718600c90b0a04e20
+Subproject commit 2bd6e7d12040659b5be66d6d9a0df55838446379