Add animation to fox image.

A CSS keyframe animation was used to make the fox image's eyes blink. (Only
on the home page, not on the about page.)

    - The eyes of the fox were made into div elements rather than part
      of the image.
    - The animation was added to the welcome style sheet.
    $ git add .
    $ git commit -F commit-message.txt
    $ git push origin master

Tests passing: 5
Tests failing: 0