Improve eslint rules (#3147)

* Add semi to ESLint rules

* Add padded-blocks to ESLint rules

* Add comma-dangle to ESLint rules

* add config/webpack and storyboard

* add streaming/

* yarn test:lint -- --fix

app/javascript/mastodon/components/relative_timestamp.js

@@ -14,7 +14,7 @@ const RelativeTimestamp = ({ intl, timestamp }) => {
 
 RelativeTimestamp.propTypes = {
   intl: PropTypes.object.isRequired,
-  timestamp: PropTypes.string.isRequired
+  timestamp: PropTypes.string.isRequired,
 };
 
 export default injectIntl(RelativeTimestamp);