Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Making the results file a proper json file

    The results.json file is currently not a properly formated json file,
    but contains one json structure per line/testcase. Whit this change, all
    test results are being collected at runtime and then written to a
    properly formated json file at the end of a test run.

    Moreover, this patch introduces 'mandatory' and 'optional' sections to
    the test suites definition files in order to clearly indicate if a test
    is part of the corresponding test scope.

    The web portal needs to be adapted accordingly to be able to read the
    new results file.

    JIRA: DOVETAIL-672

    Change-Id: Id0706c7e82622fc9c2c2fece26b2d6c07c1580be
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 69500f7..947f1bf 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 69500f77438eb6fccbb37921e612a3179c311313
+Subproject commit 947f1bf0147c40971fdae36feecd477ab3caf3b8