Test directory refactoring step 1.

Moving TestProjects and TestPackages under root 'TestAssets' folder.

Partial fix #1250

TestAssets/TestProjects/TestLibrary/Helper.cs

@@ -0,0 +1,24 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+
+namespace TestLibrary
+{
+    public static class Helper
+    {
+        /// <summary>
+        /// Gets the message from the helper. This comment is here to help test XML documentation file generation, please do not remove it.
+        /// </summary>
+        /// <returns>A message</returns>
+        public static string GetMessage()
+        {
+            return "This string came from the test library!";
+        }
+
+        public static void SayHi()
+        {
+            Console.WriteLine("Hello there!");
+        }
+    }
+}

TestAssets/TestProjects/TestLibrary/TestLibrary.xproj

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">14.0</VisualStudioVersion>
+    <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
+  </PropertyGroup>
+  <Import Project="$(VSToolsPath)\DNX\Microsoft.DNX.Props" Condition="'$(VSToolsPath)' != ''" />
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>947dd232-8d9b-4b78-9c6a-94f807d2dd58</ProjectGuid>
+    <RootNamespace>TestLibrary</RootNamespace>
+    <BaseIntermediateOutputPath Condition="'$(BaseIntermediateOutputPath)'=='' ">..\..\artifacts\obj\$(MSBuildProjectName)</BaseIntermediateOutputPath>
+    <OutputPath Condition="'$(OutputPath)'=='' ">..\..\artifacts\bin\$(MSBuildProjectName)\</OutputPath>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <SchemaVersion>2.0</SchemaVersion>
+  </PropertyGroup>
+  <Import Project="$(VSToolsPath)\DNX\Microsoft.DNX.targets" Condition="'$(VSToolsPath)' != ''" />
+</Project>

TestAssets/TestProjects/TestLibrary/project.json

@@ -0,0 +1,15 @@
+{
+    "version": "1.0.0-*",
+    "compilationOptions": {
+        "nowarn": [ "CS1591" ],
+        "xmlDoc": true,
+        "additionalArguments": [ "-highentropyva+" ]
+    },
+    "dependencies": {
+        "NETStandard.Library": "1.0.0-rc2-23805"
+    },
+
+    "frameworks": {
+        "dnxcore50": { }
+    }
+}