input: Write a python function to find the maximum consecutive sum of a list of numbers.
  assert max_consecutive_sum([1, 2, 3, -2, 5]) == 9
  assert max_consecutive_sum([-2, 1, -3, 4, -1, 2, 1, -5, 4]) == 6
  assert max_consecutive_sum([5, 4, -1, 7, 8]) == 23
output: def max_consecutive_sum(nums):
      max_sum = curr_sum = nums[0]
      for num in nums[1:]:
          curr_sum = max(num, curr_sum + num)
          max_sum = max(max_sum, curr_sum)
      return max_sum