Add WebProxySettings (use when proxying requests) (#370)

* webproxy part 1

* fixed

* Push to MyGet

* WebProxy standalone

* -n true

* nuget --- "-n true"

* AllowAutoRedirect

* .

test/WireMock.Net.Tests/ResponseBuilders/ResponseWithProxyTests.cs

@@ -2,6 +2,7 @@
 using NFluent;
 using System;
 using System.Collections.Generic;
+using System.Net.Http;
 using System.Threading.Tasks;
 using WireMock.Models;
 using WireMock.RequestBuilders;
@@ -45,6 +46,28 @@ namespace WireMock.Net.Tests.ResponseBuilders
             Check.That(responseMessage.Headers["Content-Type"].ToString()).IsEqualTo("application/json");
         }
 
+        [Fact]
+        public void Response_WithProxy_WebProxySettings()
+        {
+            // Assign
+            var settings = new ProxyAndRecordSettings
+            {
+                Url = "http://test.nl",
+                WebProxySettings = new WebProxySettings
+                {
+                    Address = "http://company",
+                    UserName = "x",
+                    Password = "y"
+                }
+            };
+            var response = Response.Create().WithProxy(settings);
+
+            // Act
+            var request = new RequestMessage(new UrlDetails($"{_server.Urls[0]}/{_guid}"), "GET", "::1");
+
+            Check.ThatAsyncCode(() => response.ProvideResponseAsync(request, _settingsMock.Object)).Throws<HttpRequestException>();
+        }
+
         public void Dispose()
         {
             _server?.Dispose();