github/training.github.com — pull request #153 by afeld (2013-12-09 20:51:09+00:00)
Title: Use HTML::Proofer

Per https://github.com/github/training.github.com/issues/129#issuecomment-30165276. The (new) tests are failing... does anyone feel strongly about me fixing them in this PR, vs. a separate one? Was gonna paste the output here, but there are "1367 failures" :grimacing: Put it in [a Gist](https://gist.github.com/afeld/da193daa4e871e4a5c41) instead.

*Technically* `master` is "broken" by these new standards, but is being incorrectly reported as "passing". P.S. this site has a *lot* of content... the `cibuild` took nearly 10 minutes on my local machine :flushed: