Added Kaminari for pagination of cats and reviews.

9 Cats per page on index, 3 reviews per cat shown.
For a sequence you usually want each element to be different. In this case you can use the argument you get from the sequence to change the text a bit:

```ruby
sequence(:review) { |n| "Cute cat #{n}" }
```

and this will generate `Cute cat 1`, `Cute cat 2`, and so on.

If you don't need the reviews to be unique, you can just use the string directly:

```ruby
factory :review do
  review "Cute cat"
end
```