Upgrade Babel to version 7.0.0 (#5925)

app/javascript/mastodon/components/column_header.js

@@ -10,8 +10,8 @@ const messages = defineMessages({
   moveRight: { id: 'column_header.moveRight_settings', defaultMessage: 'Move column to the right' },
 });
 
-@injectIntl
-export default class ColumnHeader extends React.PureComponent {
+export default @injectIntl
+class ColumnHeader extends React.PureComponent {
 
   static contextTypes = {
     router: PropTypes.object,