input: Write a function to return an array with the running total of numbers in a given list using numpy. The function should take a list as input and return an array with cumulative sums.
  import numpy as np
  def runningTotal(arr):
      return np.cumsum(arr)
  assert np.array_equal(runningTotal([1, 2, 3, 4]), [1, 3, 6, 10])
  assert np.array_equal(runningTotal([5, -2, 0, 10]), [5, 3, 3, 13])
  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: import numpy as np
  def runningTotal(arr):
      return np.cumsum(arr)