Fix `getComputedStyle` with keyframes.

Closes #549, closes #576, closes #577.
Fix #459: handling of features in jsdom.env.
Version 0.5.2
Fix #580: `getAttributeNS`  for nonextant attributes.
Pin request to 2.14. Fixes #584.
Version 0.5.3
Loosen request dependency back up.

See #584.
Clean up package.json.
Remove console.log devDependency.

This behavior was fixed in Node.js.
Parser can now be set via jsdom.env config object.
Removed assignments that accidentally created gloabal variables.
Removed references to non-existent globals.
Fix rowIndex for detached table rows
Make <img> `src`'s evaluate relative to `location.href`.

Closes #470.
Don't publish `.travis.yml`.
Updates to testing info in `Contributing.md`.
Version 0.5.4
Add a <select> test I found un-pushed.
Fixed type-o in comment.
Add (failing) test case for <input readonly="">

The readOnly attribute of the input should be true according to
  HTML4: http://www.w3.org/TR/REC-html40/intro/sgmltut.html#h-3.3.4.2 as well as
  HTML5: http://www.whatwg.org/specs/web-apps/current-work/#boolean-attributes
.