https://android-arsenal.com/details/1/2456 <– Katie likes this one 😉
https://www.bignerdranch.com/blog/expand-a-recyclerview-in-four-steps/
http://theopentutorials.com/tutorials/android/listview/android-expandable-list-view-example/
https://github.com/traex/ExpandableLayout
D20 Capstone 