oldestLivingFather.js

// Given the following data structure
// implement a oldestLivingFather method 
// that will return the name of the oldest 
// living father.

var people = [
  {
    name: 'Hank',
    age: 29,
    father: 'Don'
  },
  {
    name: 'Deborah',
    age: 30,
    father: 'Don'
  },
  {
    name: 'Danny',
    age: 24,
    father: 'Don'
  },
  {
    name: 'Don',
    age: 64,
    father: 'Haskell'
  },
  {
    name: 'Haskell',
    father: 'Finus'
  },
  {
    name: 'Finus'
  },
  {
    name: 'Jeff',
    age: 75,
    father: 'Johnny'
  }
]

oldestLivingFather(people);
// -> 'Don'