use `writeFileSync`

Thanks @thisandagain!

bin/get-localized-urls

@@ -36,9 +36,7 @@ https.get('https://resources.scratch.mit.edu/localized-urls.json', (res) => {
     res.on('end', () => {
         try {
             var urlJson = JSON.parse(urlData);
-            fs.writeFile(filename, JSON.stringify(urlJson, null, '  '), (err) => {
-                if (err) process.stdout.write(`Failed writing file: ${err.message}\n`);
-            });
+            fs.writeFileSync(filename, JSON.stringify(urlJson, null, '  '));
         } catch (e) {
             process.stdout.write(`Failed parsing url data: ${e.message}\n`);
             process.exit(1);