Updated git submodules

Project: appc master 223970340047bee364489ab06cfbfb9e413694e7

Add assertj artifact test dependency

Add new assertion libraries for writing improved unit test assertions in
a fluent style manner:
- assertj-core
- assertj-guava

Change-Id: Ifca841a88f91219c13b50f7b80c7e0fe660bea19
Issue-ID: APPC-437
Signed-off-by: Michal Kabaj <michal.kabaj@nokia.com>

diff --git a/docs/submodules/appc.git b/docs/submodules/appc.git
index 8c79009..2239703 160000 (submodule)
--- a/docs/submodules/appc.git
+++ b/docs/submodules/appc.git
@@ -1 +1 @@
-Subproject commit 8c7900939c52fb8770827c1beaac9753f42b0d02
+Subproject commit 223970340047bee364489ab06cfbfb9e413694e7