[dom] Attribute lowercasing does not appear to match browsers or web-platform-tests (#31)

I implemented the current attribute spec in jsdom pretty exactly. However, it failed the following web-platform-test ([source](https://github.com/w3c/web-platform-tests/blob/56537bab9207d0c910c49305d4b55d5d5c639dea/dom/nodes/attributes.html#L41)):

```js
test(function() {
  var el = document.createElement("div")
  el.setAttribute("ALIGN", "left")
  assert_equals(el.getAttributeNS("", "ALIGN"), null)
  assert_equals(el.getAttributeNS("", "align"), "left")
  assert_equals(el.getAttribute("align"), "left")
}, "setAttribute should lowercase its name argument (upper case attribute)")
```

In my implementation `null` is returned for all three calls, because per spec `setAttribute` doesn't actually do any lowercasing.

If this is intentional we can just update web-platform-tests. I was unclear.

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Reply to this email directly or view it on GitHub:
https://github.com/whatwg/dom/issues/31