input: Write a function to compute the running total of numbers in a given list using numpy. The function should return an array where each element is the running total of the elements up to that position in the input list.
  
  import numpy as np
  
  def runningTotal(arr):
      return np.cumsum(arr)
  
  assert list(runningTotal([1, 2, 3, 4]))==[1, 3, 6, 10]
  assert list(runningTotal([5, 5, 5, 5]))==[5, 10, 15, 20]
  assert list(runningTotal([10]))==[10]
  assert list(runningTotal([]))==[]
  assert list(runningTotal([-1, 2, -3, 4]))==[-1, 1, -2, 2]
output: import numpy as np
  
  def runningTotal(arr):
      return np.cumsum(arr)