Add deterministic build tests sample (#820)

Add deterministic build tests sample

Documentation/Examples/MSBuild/DeterministicBuild/XUnitTestProject1/UnitTest1.cs

@@ -0,0 +1,14 @@
+using System;
+using Xunit;
+
+namespace XUnitTestProject1
+{
+    public class UnitTest1
+    {
+        [Fact]
+        public void Test1()
+        {
+            new ClassLibrary1.Class1().Method();
+        }
+    }
+}