Fix broken latest download link
Fix broken latest download link

Relying on the ianyh.com hosted releases is deprecated so the `-latest.zip` doesn't exist anymore. A lot of projects seem to direct people to the Releases page so we'll do that for now. Open to suggestions otherwise.

Fixes #711
ianyh/Amethyst,ianyh/Amethyst,ianyh/Amethyst,ianyh/Amethyst,ianyh/Amethyst