Wrap

Hey all,
I think I have made some progress on .wrap(), however, I cannot get it to work with strings, only cheerio nodes. This PR contains the failing test commented out. I saw other open issues regarding string input on .replaceWith();

Any tips?

Thanks,
You can use `_.forEach` here instead--then you don't have to create a referenced to `el`. Pass it: `(this, {{ your function }}, this)`, and you won't need to close around a `self` alias, either.