Fix Capybara specs

Before we commit to removing the capybara-webkit specs, which would require figuring out what to replace them with and rewriting all the tests, I'd like to take a more organized stab at fixing the setup problems we encountered today at the Awesome Summit. 

The first step on that is getting all the tests fixed -- thus, this diff fixes the broken capybara specs. They were all either simple changes to reflect the current site markup or bugs due to the upgrade.

If the Travis CI PR is merged in, this PR should show as green, including the capybara specs. Otherwise, you can check out the branch and the tests should pass.