Initial add of chicken object and tests.
Flesh out the Chicken object, add pub sub ext.
Fix up Notification API.
Clean up a vestigial variable.
Clean up pub sub code and related tests.
Make NotificationCenter service.
Add more unit tests to notification center
Merge branch 'chicken'
Add Feed Bag object

Add FeedBag object with tests, also add code to post the didDie
notification when a chicken lays 36 eggs.
Add refill test.
Add water bottle & egg crate
Add Nest and tests.
Reset eggCount after hatching an egg.
Update README.md
Add Farmer object and tests.
Build out Farmer object (passes all tests).
Add equal(health(), 0) to did_die black-box test.
Fix up test comment.
Add FryPan object.
Update README.md