name attribute should either warn or not be deleted

Currently, any passed name attributes are bluntly removed, see row: https://github.com/derbyjs/derby-parsing/blob/master/lib/index.js#L501

It would however be nice to either know about it (e.g. console.warn if there's a name attribute) or not remove it so we can use it in our templates.

Let me know if you want me to create a PR for either.
