Changing to file level use strict statement

lib/helpers/cookies.js

@@ -1,8 +1,9 @@
+'use strict';
+
 var utils = require('./../utils');
 
 module.exports = {
   write: function write(name, value, expires, path, domain, secure) {
-    'use strict';
     var cookie = [];
     cookie.push(name + '=' + encodeURIComponent(value));
 
@@ -26,13 +27,11 @@ module.exports = {
   },
 
   read: function read(name) {
-    'use strict';
     var match = document.cookie.match(new RegExp('(^|;\\s*)(' + name + ')=([^;]*)'));
     return (match ? decodeURIComponent(match[3]) : null);
   },
 
   remove: function remove(name) {
-    'use strict';
     this.write(name, '', Date.now() - 86400000);
   }
 };