Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Add ONAP Heat testsuite

    This patch adds a testsuite for running ONAP Heat test cases.

    Change-Id: I25a35a776dd58570379c9a493dffffc53677a396
    Signed-off-by: Stamatis Katsaounis <mokats@intracom-telecom.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index de39be8..ea79f4f 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit de39be86dddc6fd590d9dbc9bad084e6be45aa13
+Subproject commit ea79f4f2ff092223237553117606cf38b8a359fe