JsonUtil unit tests

Improved code coverage + some test class refactor

Change-Id: Ie69f4a699f7f924438eda24014c44fe54643e707
Issue-ID: APPC-724
Signed-off-by: Jakub Dudycz <jakub.dudycz@nokia.com>
diff --git a/appc-common/src/test/resources/valid.json b/appc-common/src/test/resources/valid.json
new file mode 100644
index 0000000..6ce80f3
--- /dev/null
+++ b/appc-common/src/test/resources/valid.json
@@ -0,0 +1,4 @@
+{
+  "name": "dummy name",
+  "value": 99
+}
\ No newline at end of file