Make contributor links point to GitHub profiles

Previously, they pointed to GitHub API urls.
Point CI urls to Travis CI

They previously pointed to a site that is currently down.
Use contributor's html_url as href for their anchor tag

GitHub has added html_url to the user object throughout their
API responses, per my support request, so we can now make use of it
in this page.
Merge pull request #265 from NateEag/gh-pages

Point contributor links to GitHub profiles