Add Leaderboard that can filter Teams and top 5 Favorites.

Assumptions
* Assumed TOP_LIMIT could not be exceeded (since it was the default parameter) so I defined it as 25.
* Assumed the desired filter column was the current_amount provided by the API call.

Notes
* I opted to pre-populate the database with the api data from the seeds file.
* I added 60 minute caching based on the query parameter team_id