Unable to update a message using UpdateAsync

[farhanalam]

Here is my code

var slackClient = new SlackTaskClient(token);
var postResponse = await slackClient.PostMessageAsync("#general", "test");
var updateResponse = await slackClient.UpdateAsync(postResponse.ts, "#general", "test 2.0");

The response I get (as observed in Fiddler) is

{"ok":false,"error":"invalid_arguments","deprecated_argument":"as_user"}

I believe this requires a similar fix to #217

[VladyslavLishchyna]

try get channel from postResponse and put it to UpdateAsync override #general its works for me)

[xt0rted]

I just ran into this issue and was able to get it to work by setting as_user: true on the update method. This shows the message as edited though, which other integrations don't seem to do 🤷‍♂️