Use Kaminari's default config for (max_)per_page

Use Kaminari's config which is generated from running `rails g kaminari:config`.

You will still need to call `paginate` outside the `get`. I was looking for a way to do this automatically but couldn't think of an easy/quick implementation.
Merge pull request #9 from ericboehs/patch-1

Use Kaminari's default config for (max_)per_page