input: Write a function to return an array with the running total of numbers in a given list using numpy. The function should accept a list as input and use numpy's cumsum function to compute the running total.
  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([0, -1, 1, -2]), [0, -1, 0, -2])
  assert np.array_equal(runningTotal([5]), [5])
  assert np.array_equal(runningTotal([]), [])
  assert np.array_equal(runningTotal([10, 20, 30, 40, 50]), [10, 30, 60, 100, 150])
output: import numpy as np
  
  def runningTotal(arr):
      return np.cumsum(arr)