Added Kaminari for pagination of cats and reviews.

9 Cats per page on index, 3 reviews per cat shown.
I would consider moving the *9* to a constant:

```ruby
class CatsController < ApplicationController
  CATS_PER_PAGE = 9

  def index
    @cats = Cat.order(created_at: :desc).page(params[:page]).per(CATS_PER_PAGE)
  end
end
```

Now you can use this constant in your tests so if you ever change the number of entries per page, the tests are automatically updated:

```ruby
scenario "limit number of cats per page" do
  # here we use the constant to avoid hard-coding any numbers in the program
  modern_cats = FactoryGirl.create_list(:cat, CatsController::CATS_PER_PAGE)
  old_cat = FactoryGirl.create(:cat, updated_at: Date.yesterday)

  visit cats_path

  # check to see that only the modern cats are being shown
end
```