Fixed restricted headers on response (#71)

* Fixed restricted headers on response

* appveyor

examples/WireMock.Net.ConsoleApplication/MainApp.cs

@@ -21,6 +21,10 @@ namespace WireMock.Net.ConsoleApplication
                 Urls = new[] { url1, url2, url3 },
                 StartAdminInterface = true,
                 ReadStaticMappings = true,
+                //ProxyAndRecordSettings = new ProxyAndRecordSettings
+                //{
+                //    SaveMapping = true
+                //},
                 PreWireMockMiddlewareInit = app => { System.Console.WriteLine($"PreWireMockMiddlewareInit : {app.GetType()}"); },
                 PostWireMockMiddlewareInit = app => { System.Console.WriteLine($"PostWireMockMiddlewareInit : {app.GetType()}"); }
             });
@@ -30,6 +34,12 @@ namespace WireMock.Net.ConsoleApplication
 
             // server.AllowPartialMapping();
 
+            // .WithHeader("Stef", "Stef")
+            //server
+            //    .Given(Request.Create().WithPath("*"))
+            //    .RespondWith(Response.Create()
+            //    .WithProxy("http://restcountries.eu"));
+
             server
                 .Given(Request.Create().WithPath("/headers", "/headers_test").UsingPost().WithHeader("Content-Type", "application/json*"))
                 .RespondWith(Response.Create()