Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "WIP: Test case description for vping test cases"
  - WIP: Test case description for vping test cases

    Adding test case descriptions for both vping test cases implemented in
    Functest. Test case 1 makes use of the config drive mechanism of
    Nova to pass a test script. Test case 2 uses SSH to transfer and execute
    a script on one VM.

    Change-Id: Ic8be6ad4dfd4b0e7661064506b0ae92db2fc1463
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 7ed1cf1..a0f7d4b 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 7ed1cf189676693d84c9d48bb964c178b16bae76
+Subproject commit a0f7d4bcd3d1077c8211d706d0cdc49dfbbddc01