input: Write a function to calculate the running total of numbers in a given list using numpy. Return an array with the cumulative sum of the input list.
  assert np.array_equal(runningTotal([1, 2, 3, 4]), [1, 3, 6, 10])
  assert np.array_equal(runningTotal([5, -2, 7, 0]), [5, 3, 10, 10])
  assert np.array_equal(runningTotal([]), [])
  assert np.array_equal(runningTotal([-1, -1, -1, -1]), [-1, -2, -3, -4])
  assert np.array_equal(runningTotal([10]), [10])
output: def runningTotal(lst):
      return np.cumsum(lst)