Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Running BGPVPN Tempest tests as tempest_custom test

    We need to disable one BGPVPN tempest test due to a bug in ODL. Since
    the SDNVPN test framework does not allow for disabling a single test
    case, we are switching to tempest_custom.

    Change-Id: Ifbd7c1dc5e799d6a6c774e08e9fc1a3b2294b47c
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 3715cbf..3bee66e 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 3715cbfc05791080be4d7c43b0ff697fad298b43
+Subproject commit 3bee66ed9be2e78b1c11b095deb2205ce6ff4865