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 of numbers as input and use numpy's `cumsum` function to calculate 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, 0, 0, 0]), [0, 0, 0, 0])
  assert np.array_equal(runningTotal([-1, -2, -3, -4]), [-1, -3, -6, -10])
  assert np.array_equal(runningTotal([]), [])
  assert np.array_equal(runningTotal([1]), [1])
output: import numpy as np
  
  def runningTotal(arr):
      return np.cumsum(arr)