Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Update classes in testcase.py

    1. Remove the functions which are not called anywhere
    2. Change some class methods to be static methods and instance methods

    Change-Id: I2e754cdff61aa34ffe899e352653ff767d4ac69d
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 33ffeda..41392d6 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 33ffeda0ebd938087fb43c137e7ed8873754c03e
+Subproject commit 41392d61f366130d089bccfff5cd1b08bc0bb5d2