convert js-cookie dependency to an npm module

app/assets/javascripts/application.js

@@ -20,7 +20,7 @@ require('vendor/jquery.waitforimages');
 require('vendor/jquery.caret');
 require('vendor/jquery.atwho');
 require('vendor/jquery.scrollTo');
-window.Cookies = require('vendor/js.cookie');
+window.Cookies = require('js-cookie');
 require('./autosave');
 require('bootstrap/js/affix');
 require('bootstrap/js/alert');

app/assets/javascripts/cycle_analytics/cycle_analytics_bundle.js.es6

@@ -3,7 +3,7 @@
 /* global Flash */
 
 window.Vue = require('vue');
-window.Cookies = require('vendor/js.cookie');
+window.Cookies = require('js-cookie');
 
 function requireAll(context) { return context.keys().map(context); }
 requireAll(require.context('./svg', false, /^\.\/.*\.(js|es6)$/));

app/assets/javascripts/merge_request_tabs.js.es6

@@ -4,7 +4,7 @@
 /* global Flash */
 
 require('./breakpoints');
-window.Cookies = require('vendor/js.cookie');
+window.Cookies = require('js-cookie');
 require('./flash');
 
 /* eslint-disable max-len */

package.json

@@ -23,6 +23,7 @@
     "jquery": "2.2.1",
     "jquery-ui": "github:jquery/jquery-ui#1.11.4",
     "jquery-ujs": "1.2.1",
+    "js-cookie": "^2.1.3",
     "mousetrap": "1.4.6",
     "pikaday": "^1.5.1",
     "select2": "3.5.2-browserify",

spec/javascripts/test_bundle.js

@@ -7,7 +7,7 @@ jasmine.getJSONFixtures().fixturesPath = 'base/spec/javascripts/fixtures';
 // include common libraries
 window.$ = window.jQuery = require('jquery');
 window._ = require('underscore');
-window.Cookies = require('vendor/js.cookie');
+window.Cookies = require('js-cookie');
 window.Vue = require('vue');
 window.Vue.use(require('vue-resource'));
 require('jquery-ujs');