Merge pull request #1 from spencerbaynton/gh-pages

Added Designer News PSD
Updated site with area for contributors; added Designer News UI by Spencer to the site
Add contributor links to README
Add GitHub UI; refactor some of the page's styles
Add new PSD: Heroku UI; update bug in GitHub UI
Update download tracking to use Segment.io
Track subscriptions and tweets with Segment.io
Add jQuery; fix tracking links
Update GitHub UI to GitHub Repository Next UI; close issue gh-2
Remove snippet for tracking shares
Add Rdio UI; cleanup keywords