Update to 8.1.0 - a new logger implemented as a solution for https://github.com/kataras/iris/issues/680

Former-commit-id: 765b43602655fad7f525ca7a5f7f297a6167d075

_examples/http_request/request-logger/request-logger-file/main.go

@@ -36,7 +36,7 @@ func main() {
 	// http://localhost:8080/1
 	// http://localhost:8080/2
 	// http://lcoalhost:8080/notfoundhere
-	app.Run(iris.Addr(":8080"))
+	app.Run(iris.Addr(":8080"), iris.WithoutServerError(iris.ErrServerClosed))
 }
 
 // get a filename based on the date, file logs works that way the most times