We've provided the code for a basic list of items. Now it's your turn to extend it. Do your work in app/application.rb.

In applications built on Rack, we use the noun "route" to to refer to a path that the application has a special response to.

Thus the /shoes "route" shows information about shoes. The /profile "route" shows information about the logged-in user. The /logout route does something to delete some information that let the server know the user was logged in.

1. Create a new class array called @@cart to hold any items in your cart
2. Create a new route called /cart to show the items in your cart
3. Create a new route called /add that takes in a GET param with the key item. This should check to see if that item is in @@items and then add it to the cart if it is. Otherwise give an error