radixSort = array => {
  const max = maximumKey(array);
  const digitsMax =
    max === 0 ? 1 : 1 + Math.floor(Math.log(max) / Math.log(10)); // log base 10

  for (let i = 0; i < digitsMax; i++) {
    array = auxiliaryCountingSort(array, i);
  }

  return array;
}
Sorts an array of objects according to their 'key' property
Every object inside the array MUST have the 'key' property with
a integer value.

Asymptotic Complexity: O(array.length * d), where 'd' represents
the amount of digits in the larger key of the array

@param Array
@return Array