Add paging to homepage carousels

[cassidyjames]

Since the API server supports more than just five apps, and we have weird wrapping (see #462), I wonder if it would make sense to page the carousels on the home page. I think this was in the initial designs as well.

This could lead to more discovery and promoting a larger variety of apps on the home page.

[cassidyjames]

This would also let us just display however many fit without wrapping in each row instead of hardcoding to five items, since the end of the list would go to the next page.

[btkostner]

As a note, I plan on extending and making the API endpoints of houston v2 much better. This should allow more control over pagination and filtering.