upgrade to winston 3.1, closes #6590 (#6838)

* upgrade to winston 3.1

* fix winston in web/install and tests

test/defer-logger.js

@@ -1,40 +1,37 @@
 'use strict';
 
-var util = require('util');
 var winston = require('winston');
-
-function DeferLogger(options) {
-	options = options || {};
-
-	this.name = 'DeferLogger';
-	this.level = options.level || 'info';
-
-	this.logged = options.logged;
-}
-
-util.inherits(DeferLogger, winston.Transport);
-
-DeferLogger.prototype.log = function log(level, msg, meta, callback) {
-	this.logged.push([level, msg, meta]);
-	callback(null, true);
-};
+var Transport = require('winston-transport');
 
 var winstonLogged = [];
 
+class DeferLogger extends Transport {
+	constructor(opts) {
+		super(opts);
+		this.logged = opts.logged;
+	}
+
+	log(info, callback) {
+		setImmediate(() => {
+			this.emit('logged', info);
+		});
+
+		this.logged.push([info.level, info.message]);
+		callback();
+	}
+}
+
 before(function () {
 	// defer winston logs until the end
-	winston.remove(winston.transports.Console);
+	winston.clear();
 
-	winston.add(DeferLogger, {
-		logged: winstonLogged,
-	});
+	winston.add(new DeferLogger({ logged: winstonLogged }));
 });
 
 after(function () {
 	console.log('\n\n');
 
-	var con = new winston.transports.Console();
 	winstonLogged.forEach(function (args) {
-		con.log(args[0], args[1], args[2], function () {});
+		console.log(args[0] + ' ' + args[1]);
 	});
 });