Test that JsonObject.size() is increased when values are added

srcs/srcs.vcxproj

@@ -66,8 +66,12 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClInclude Include="JsonObject.h" />
+    <ClInclude Include="JsonValue.h" />
     <ClInclude Include="StaticJsonBuffer.h" />
   </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="JsonObject.cpp" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>