Linked Lists - Length & Count
Implement Length() to count the number of nodes in a linked list.
Implement Count() to count the occurrences of an integer in a linked list.
I've decided to bundle these two functions within the same Kata since they are both very similar.
The `push()`/`Push()` and `buildOneTwoThree()`/`BuildOneTwoThree()` functions do not need to be redefined.

class Node(object):
  def __init__(self, data):
    self.data = data
    self.next = None
    
def length(node):
  if node:
    return 1 + length(node.next)
  return 0
  
def count(node, data):
  if node:
    if node.data == data:
      return 1 + count(node.next, data)
    return count(node.next, data)
  return 0
class Node(object):
  def __init__(self, data):
    self.data = data
    self.next = None
    
def length(node):
  if node:
    return 1 + length(node.next)
  return 0
  
def count(node, data):
  if node:
    if node.data == data:
      return 1 + count(node.next, data)
    return count(node.next, data)
  return 0