Babel balks when transpiling symbol-tree

[czardoz]

This is due to a duplicate declaration in SymbolTree.js:

symbol-tree/lib/SymbolTree.js: Duplicate declaration "index"
  481 |                 }
  482 | 
> 483 |                 let index = childNode.getCachedIndex(parentNode);
      |                     ^
  484 | 
  485 |                 if (index >= 0) {
  486 |                         return index;

[Joris-van-der-Wel]

Fixed in 3.1.4, thanks.

if you reinstall jsdom, npm should pick up this version automatically