update socket.io to 3.x

public/core/app.js

@@ -76,6 +76,7 @@ class App {
     page('/settings', this.HandleSettingsIndex);
     page('/profile', this.HandleUserIndex);
     page('/worlds', this.HandleIndex);
+    page('/:user', this.HandleUserWorlds);
     page('/:user/worlds', this.HandleUserWorlds);
     page('/:user/:type/:name/edit/:file', this.HandleFileEdit);
     page('/:user/:space', this.HandleParsableRequestWithID);

public/index.js

@@ -11,7 +11,7 @@ loadjs([
 
 loadjs([
     '/index.css',
-    '/lib/socket.io.js',
+    '/lib/socket.io.min.js',
     '/lib/he.js',
     '/lib/locale/polyglot.min.js',
     '/lib/hashids.min.js',