input: Write a python function to sum elements of an array faster using a loop.
  assert faster_sum([1, 2, 3, 4, 5]) == 15
  assert faster_sum([10, 20, 30, 40, 50]) == 150
  assert faster_sum([5, 10, 15, 20, 25]) == 75
output: def faster_sum(arr):
      total = 0
      for num in arr:
          total += num
      return total