Add support for Basic Access Authentication in .NET RemoteWebDriver

The username and password of the Uri wasn't used by the HttpWebRequest.

Usage example
new RemoteWebDriver(new Uri("http://user:pass@example.com/wd/hub"), DesiredCapabilities.Chrome());

Signed-off-by: Jim Evans <james.h.evans.jr@gmail.com>

dotnet/src/webdriver/Remote/HttpCommandExecutor.cs

@@ -149,6 +149,13 @@ private static string GetTextOfWebResponse(HttpWebResponse webResponse)
         private HttpResponseInfo MakeHttpRequest(HttpRequestInfo requestInfo)
         {
             HttpWebRequest request = HttpWebRequest.Create(requestInfo.FullUri) as HttpWebRequest;
+            if (!string.IsNullOrEmpty(requestInfo.FullUri.UserInfo) && requestInfo.FullUri.UserInfo.Contains(":"))
+            {
+                string[] userInfo = this.remoteServerUri.UserInfo.Split(new char[] { ':' }, 2);
+                request.Credentials = new NetworkCredential(userInfo[0], userInfo[1]);
+                request.PreAuthenticate = true;
+            }
+
             request.Method = requestInfo.HttpMethod;
             request.Timeout = (int)this.serverResponseTimeout.TotalMilliseconds;
             request.Accept = RequestAcceptHeader;