Update stylesheets to use sass in application, add underline on hover and remove black background, add css for catalog
Modify price to include helper method number_to_currency
Update to include banner, columns and side navigation
Add assertions to test catalog's html
Turn on caching
Create class method 'latest' to retrieve latest update product
Update code to include caching to store and entry
Rearrange code to avoid going futher than 80 character per line