Update git submodules

* Update docs/submodules/dovetail from branch 'stable/fraser'
  - Update test list for OS interop tests

    The OpenStack Interop WG has recently deprecated [1] 4 cinder volume
    reservation tests. As a result, they are not part of Functest's set of
    interop tests anymore. This patch cleans up the test case validation
    list for the web portal.

    [1] https://review.openstack.org/#/c/583970/

    Change-Id: I183602b099cb4d44c6cb3d21af6acaa4d3ee01ca
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>
    (cherry picked from commit 16ec1f400882a80c2762c2b1667af81089555591)

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 79387eb..15e67ea 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 79387ebf2a832773108569b11f46432254239019
+Subproject commit 15e67ead211b39f2c9793e89a0058ba6bd75cb87