allow to read file that saved in other encodings then utf-8

lib/storage.js

@@ -41,9 +41,7 @@ const lock = require('./lock');
 const readFile = function(fileName, callback, times) {
   times = times || 0;
 
-  fs.readFile(fileName, {
-    encoding: 'utf8'
-  }, function(error, object) {
+  fs.readFile(fileName, function(error, object) {
     if (!error) {
       return callback(null, object);
     }