Webpack (#15)

See https://github.com/flarum/core/pull/1367

* Replace gulp with webpack and npm scripts for JS compilation
* Set up Travis CI to commit compiled JS
* Restructure `js` directory; only one instance of npm, forum/admin are "submodules"
* Restructure `less` directory

extensions/likes/js/src/forum/components/PostLikedNotification.js

@@ -0,0 +1,31 @@
+import Notification from 'flarum/components/Notification';
+import username from 'flarum/helpers/username';
+import punctuateSeries from 'flarum/helpers/punctuateSeries';
+
+export default class PostLikedNotification extends Notification {
+  icon() {
+    return 'far fa-thumbs-up';
+  }
+
+  href() {
+    return app.route.post(this.props.notification.subject());
+  }
+
+  content() {
+    const notification = this.props.notification;
+    const user = notification.sender();
+    const auc = notification.additionalUnreadCount();
+
+    return app.translator.transChoice('flarum-likes.forum.notifications.post_liked_text', auc + 1, {
+      user,
+      username: auc ? punctuateSeries([
+        username(user),
+        app.translator.transChoice('flarum-likes.forum.notifications.others_text', auc, {count: auc})
+      ]) : undefined
+    });
+  }
+
+  excerpt() {
+    return this.props.notification.subject().contentPlain();
+  }
+}