Update prettier to 16.6.4 (codesandbox#1696)

Author: CompuIves

packages/app/src/app/utils/prettify.js

@@ -148,7 +148,7 @@ export default function prettify(
 ) {
   const mode = getMode(title);
 
-  worker = worker || new Worker('/static/js/prettier/worker-1.15.1.js');
+  worker = worker || new Worker('/static/js/prettier/worker-1.16.4.js');
 
   return new Promise((resolve, reject) => {
     if (cancellationToken && cancellationToken.isCancellationRequested) {