Removed custom Flex component

frontend/components/PublishingInfo/PublishingInfo.js

@@ -2,7 +2,7 @@ import React from 'react';
 import moment from 'moment';
 
 import { Avatar } from 'rebass';
-import Flex from 'components/Flex';
+import { Flex } from 'reflexbox';
 
 import styles from './PublishingInfo.scss';
 
@@ -29,4 +29,4 @@ PublishingInfo.propTypes = {
   updatedAt: React.PropTypes.string.isRequired,
 };
 
-export default PublishingInfo;
+export default PublishingInfo;