Move the stylesheets out stylesheets/libs.

This is the first step in better organizing the stylesheets to be broken apart
into separate files to be more digestible.
Split apart the cookbooks stylesheet.

Create smaller files logically named by the areas of Cookbooks they pertain to.
Sprockets requires_tree for the cookbooks styles, meaning that any file added to
the folder will automatically be included.
Remove empty globalcolumn stylesheet.
Move the user styles into a directory.
Increase the capybara timeout.
Merge pull request #391 from opscode/split_up_stylesheets

Split up the Supermarket stylesheets to be more digestible
Add and configure the sitemap_generator gem.

Supermarket needs a sitemap, and the sitemap_generator gem generates sitemaps.
This commit does not include the setup and configuration of a cron job or deploy
task to refresh the sitemap.
Ensure the sitemap is created when Travis CI runs.

When Travis CI runs the specs, ensure that a sitemap is successfully generated
(without pinging search engines).
Create Sidetiq worker to refresh sitemap daily.

Using the sitemap_generator gem, the Sidetiq worker refreshes the sitemap daily
at midnight and pings the search engines.