Adding a unit test on DateTime usage

#256

Jint.Tests/Runtime/EngineTests.cs

@@ -950,6 +950,17 @@ namespace Jint.Tests.Runtime
             Assert.Equal(0, result);
         }
 
+        [Fact]
+        public void LocalDateTimeShouldNotLoseTimezone()
+        {
+            var date = new DateTime(2016, 1, 1, 13, 0, 0, DateTimeKind.Local);
+            var engine = new Engine().SetValue("localDate", date);
+            engine.Execute(@"localDate");
+            var actual = engine.GetCompletionValue().AsDate().ToDateTime();
+            Assert.Equal(date.ToUniversalTime(), actual.ToUniversalTime());
+            Assert.Equal(date.ToLocalTime(), actual.ToLocalTime());
+        }
+
         [Fact]
         public void UtcShouldUseUtc()
         {