make use of es6-shim

It's mainly because of Object.setPrototypeOf()

index.js

@@ -1,3 +1,4 @@
+require('es6-shim')
 module.exports = require('./lib')
 
 /**package

lib/cli.js

@@ -7,6 +7,7 @@ if (process.getuid && process.getuid() === 0) {
 }
 
 process.title = 'sinopia'
+require('es6-shim')
 
 try {
   // for debugging memory leaks

lib/logger.js

@@ -95,7 +95,7 @@ for (var l in levels) {
 }
 
 function pad(str) {
-  if (str.length < max) return str + Array(max - str.length + 1).join(' ')
+  if (str.length < max) return str + ' '.repeat(max - str.length)
   return str
 }
 
@@ -131,7 +131,7 @@ function print(type, msg, obj, colors) {
     }
 
     if (typeof(str) === 'string') {
-      if (!colors || ~str.indexOf('\n')) {
+      if (!colors || str.contains('\n')) {
         return str
       } else if (is_error) {
         return '\033[31m' + str + '\033[39m'

lib/storage.js

@@ -462,7 +462,7 @@ Storage.prototype._sync_package_with_uplinks = function(name, pkginfo, options,
   }
 
   async.map(uplinks, function(up, cb) {
-    var _options = Object.create(options)
+    var _options = Object.assign({}, options)
     if (Utils.is_object(pkginfo._uplinks[up.upname])) {
       var fetched = pkginfo._uplinks[up.upname].fetched
       if (fetched && fetched > (Date.now() - up.maxage)) {

lib/streams.js

@@ -9,7 +9,7 @@ module.exports.UploadTarballStream = UploadTarball
 //
 function ReadTarball(options) {
   var self = new Stream.PassThrough(options)
-  self.__proto__ = ReadTarball.prototype
+  Object.setPrototypeOf(self, ReadTarball.prototype)
 
   // called when data is not needed anymore
   add_abstract_method(self, 'abort')
@@ -24,7 +24,7 @@ Util.inherits(ReadTarball, Stream.PassThrough)
 //
 function UploadTarball(options) {
   var self = new Stream.PassThrough(options)
-  self.__proto__ = UploadTarball.prototype
+  Object.setPrototypeOf(self, UploadTarball.prototype)
 
   // called when user closes connection before upload finishes
   add_abstract_method(self, 'abort')

package.yaml

@@ -25,6 +25,7 @@ dependencies:
   cookies: '>=0.5.0 <1.0.0-0'
   request: '>=2.31.0 <3.0.0-0'
   async: '>=0.9.0 <1.0.0-0'
+  es6-shim: '>=0.20 <1.0.0-0'
 
   # 2.x and 3.x have the same interface
   semver: '>=2.2.1 <4.0.0-0'

test/functional/index.js

@@ -1,3 +1,4 @@
+require('es6-shim')
 require('./lib/startup')
 
 var assert = require('assert')