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/features/compose/components/warning.js

@@ -4,7 +4,7 @@ import PropTypes from 'prop-types';
 class Warning extends React.PureComponent {
 
   static propTypes = {
-    message: PropTypes.node.isRequired
+    message: PropTypes.node.isRequired,
   };
 
   render () {