Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - [bugfix] easy_install: not found

    Remove easy_install because it will be installed later.

    Change-Id: I29f425e0a5784b581a5b65ea5c8f8db66fc9dc8e
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index eefdd18..6bda989 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit eefdd18e83e6aa15f8abf9671822f3a623c17171
+Subproject commit 6bda989aab98198118d59b6a16da05d7aef74265