refactor(logger): Refactor logger.js

Use class style implement write interface

lib/logger.js

@@ -1,23 +1,23 @@
 'use strict'
-var winston = require('winston')
+const winston = require('winston')
-winston.emitErrs = true
 
-var logger = new winston.Logger({
+class Logger extends winston.Logger {
+  // Implement stream.writable.write interface
+  write (chunk) {
+    this.info(chunk)
+  }
+}
+
+module.exports = new Logger({
   transports: [
     new winston.transports.Console({
       level: 'debug',
       handleExceptions: true,
       json: false,
-      colorize: true,
+      colorize: false,
       timestamp: true
     })
   ],
+  emitErrs: true,
   exitOnError: false
 })
-
-module.exports = logger
-module.exports.stream = {
-  write: function (message, encoding) {
-    logger.info(message)
-  }
-}