Session08 - Generators, Decorators, Context Managers, Iterators

You make things a bit harder for yourself than you need to by setting `self.start` to a value other than the incoming value of `start`.  Think of `self.current` as the changeable value that will be updated each call to `next`, and allow `self.start` to function as a permanent record of what the first value returned should be.  That will ease the rest of your work considerably.