notifyslack.cs

var httpWebRequest = (HttpWebRequest) WebRequest.Create("https://hooks.slack.com/services/XXXXXXXXX/XXXXXXXXXXX/XXXXXXXXXXXXXXXXXXXXXXX");
httpWebRequest.ContentType = "text/json";
httpWebRequest.Method = "POST";

using(var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream())) {
    string json = "{\"text\":\"test message from Aras Innovator to Slack\"," +
        "\"username\":\"Innovator\"}";

    streamWriter.Write(json);
    streamWriter.Flush();
    streamWriter.Close();
}

var httpResponse = (HttpWebResponse) httpWebRequest.GetResponse();
using(var streamReader = new StreamReader(httpResponse.GetResponseStream())) {
    var result = streamReader.ReadToEnd();
}
return this;