input: Write a python function to find the sum of numbers in a given range recursively.
  assert rangeSum(1, 5) == 15
  assert rangeSum(3, 7) == 25
  assert rangeSum(10, 10) == 10
output: def rangeSum(start, end):
      if start > end:
          return 0
      return start + rangeSum(start + 1, end)