Added asset manager.

scripts/bundle.js

@@ -29,7 +29,8 @@ const outputFix = (output, dir) => {
   let match;
   while(!(match = matches.next()).done) {
     const exp = new RegExp(`${match.value[1]}\.`, 'gm');
-    scanFile(path.join(dir, match.value[2]), dir);
+    const filePath = path.join(dir, match.value[2]);
+    scanFile(filePath, path.dirname(filePath));
     out = out.replace(match.value[0], '').replace(exp, 'exports.');
   }