Duplicate member in object definition

If you try to lint [key.js](https://github.com/jupiterjs/syn/blob/master/key.js) you get the following errors

[line 222](https://github.com/jupiterjs/syn/blob/master/key.js#L222), Duplicate member '-'.
[line 223](https://github.com/jupiterjs/syn/blob/master/key.js#L223), Duplicate member '.'.
[line 224](https://github.com/jupiterjs/syn/blob/master/key.js#L224), Duplicate member '/'.

I guess only the second declaration of those symbols is needed.