Bonus: Friend View Controller + Backend

[Cwang4749]

• Reuse home view controller

• Modify layout

  • Add Name Label for other user
  • Remove Total Change label
  • Change placement of balance label
  • Add follow button

• Add "Following": array of user_ids(object_ids) as new attribute to class: "users"

• "follow" button adds user_id to user in "Following" attribute of "users" class