优化

utils/logger.js

@@ -16,10 +16,10 @@ function logger(message) {
   info(message);
 }
 
-logger.prototype.warning = warning;
+logger.warning = warning;
 
-logger.prototype.info = info;
+logger.info = info;
 
-logger.prototype.error = error;
+logger.error = error;
 
 module.exports = logger;