hash: return SHA -> file

lib/hash.js

@@ -11,7 +11,7 @@ import { createHash } from 'crypto';
 export default async function hashes (files) {
   const entries = await Promise.all(files.map(async (file) => {
     const data = await fs.readFile(file);
-    return [file, hash(data)];
+    return [hash(data), file];
   }));
   return new Map(entries);
 }