Updated git submodules

Project: ccsdk/sli/core master 2a7f6affcecfcd2a7f9db3731884699f1bacff1c

Add test cases for MdsalHelper

Add test cases for MdsalHelper methods toBuilder() and toProperties().
This requires a Yang model, so added a copy of sliapi/model to sli, since
could not use sliapi directly otherwise would create circular
dependency (since sliapi depends on sli).

Change-Id: I4824afe250f93428c73dbeec9f4a4c36ee4f76e6
Issue-ID: CCSDK-106
Signed-off-by: Dan Timoney <dtimoney@att.com>

diff --git a/docs/submodules/ccsdk/sli/core.git b/docs/submodules/ccsdk/sli/core.git
index bbf0e9f..2a7f6af 160000 (submodule)
--- a/docs/submodules/ccsdk/sli/core.git
+++ b/docs/submodules/ccsdk/sli/core.git
@@ -1 +1 @@
-Subproject commit bbf0e9ff14d10f46235d4282dce5b9c560f26321
+Subproject commit 2a7f6affcecfcd2a7f9db3731884699f1bacff1c