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/reducers/meta.js

@@ -4,7 +4,7 @@ import Immutable from 'immutable';
 const initialState = Immutable.Map({
   streaming_api_base_url: null,
   access_token: null,
-  me: null
+  me: null,
 });
 
 export default function meta(state = initialState, action) {