Swipe down refresh animation

[leesunny790]

• no gradle files :)

Using RecyclerRefreshLayout:
https://github.com/dinuscxj/RecyclerRefreshLayout

Reference:
https://guides.codepath.com/android/implementing-pull-to-refresh-guide

Notes from last PR:

• the RecyclerRefreshLayout needs to be constrained to the bottom of the leaderboard title since right now it's on top of it (maybe wrap in a constraint layout? or is there a better solution)
• can we use a custom animation with this framework? (i.e. like the custom ferris wheel animation Design made last year)