Add optional helper

[josephmancuso]

This is really cool helper that allows you to wrap any object in this helper and call attributes or methods on it even if they don't exist. If they exist then it will return the method, if it doesn't exist it will return None.

This gets around this code example:

def show(self):
    user = User.find(1)
    if user and user.id == 5:
        # do code
        ...

Now we can use this optional helper

def show(self):
    if optional(User.find(1)).id == 5:
        # do code
        ...

If the user id exists it will return the ID, else it will return None