Create step file and first step for list screencast Scenario

There is no definition for "I am a guest" as that is the defult
user.

For a screencast exists we use a new Catalog object and stub out
the :all method that shoudl return an array of hashes.

When this test is ran, we see that Catalog does not exits.
This helps us build out our application.
Create catalog module to addres failing step definition test.

This test fails beacuse this step is using stub and cucumber
does not come with rspec doubles by default and needs to be
added

https://github.com/cucumber/cucumber/wiki/Mocking-and-Stubbing-with-Cucumber
Write step definitions and make them pass.

All step definitions will pass unles you write your tests inside
them. You can use rspec to help you write these.