Update dependencies.

Most notably, Sidekiq 3.0.0.
Merge pull request #237 from opscode/update_dependencies

Update dependencies.
Fix cookbook_following_spec file name typo.
Merge pull request #239 from opscode/fix_spec_typo

Fix cookbook_following_spec file name typo.
Cookbook versions have their own show page.

Its template is more or less copied directly from cookbooks/show. If we
determine that the two should remain in near-lockstep, we can extract
partials for the job.
Order cookbook versions on a monotonic attribute
Cookbooks link to each of their published versions
JS specs are passing, and running on Travis