Added handwritten test for h_action to C#

src/bindings/dotnet/test/hammer_hand_tests.cs

@@ -0,0 +1,18 @@
+namespace Hammer.Test
+{
+  using NUnit.Framework;
+  [TestFixture]
+  public partial class HammerTest
+  {
+    [Test]
+    public void TestAction()
+    {
+      Parser parser = Hammer.Action(Hammer.Sequence(Hammer.Choice(Hammer.Token("a"),
+                                                                  Hammer.Token("A")),
+                                                    Hammer.Choice(Hammer.Token("b"),
+                                                                  Hammer.Token("B"))),
+                                    (HAction)(x => char.ToUpper(((string)x)[0])));
+                                                                  
+    }
+  }
+}