Explicitly sort file list before generating build ID

src/build/generate-scaffolding-build-id.js

@@ -18,7 +18,7 @@ const files = [
   path.join(root, 'webpack.config.js'),
   path.join(root, 'package.json'),
   path.join(root, 'package-lock.json')
-];
+].sort();
 for (const file of files) {
   console.log(file);
   const stat = fs.statSync(file);