Add two tests for project model server

TestAssets/ProjectModelServer/DthTestProjects/src/EmptyNetCoreApp/Program.cs

@@ -0,0 +1,13 @@
+using System;
+
+namespace Misc.DthTestProjects.SimpleConsoleApp
+{
+    public class Program
+    {
+        public int Main(string[] args)
+        {
+            Console.WriteLine("Hello, world.");
+            return 0;
+        }
+    }
+}

TestAssets/ProjectModelServer/DthTestProjects/src/EmptyNetCoreApp/project.json

@@ -0,0 +1,15 @@
+{
+  "dependencies": {},
+  "frameworks": {
+    "netcoreapp1.0": {
+      "imports": "dnxcore50",
+      "dependencies": {
+        "Microsoft.NETCore.App": {
+          "type": "platform",
+          "version": "1.0.0-rc2-23931"
+        },
+        "Newtonsoft.Json": "8.0.3"
+      }
+    }
+  }
+}