Created single-view application to demonstrate async testing

It's going to be a horse race. Woooo!
Work in progress commit

This makes the 2horse race controller, but it doesn't work yet
Basic horse race functionality is now complete!

Both horses finish at the same time, but the callbacks and things are
all working as expected. Time to write some tests
Implemented the random animation duration

One of the horses will actually win now
Creates an async test which checks that the horse race callbacks work

It's easy to make it fail by changing the duration of the test or the
race
Adds a really simple async test

This is the traditional async "sleep" test that everybody uses
Adds a test which uses the convenience of KVO expectations

This is pretty neat.
Adds the license header files
Adds the daily thumbnail
Updates for beta 4

Including array syntax and access modifiers
Created structure for the async testing article

No content yet
Completed async testing introduction
Completed async writeup
Add screenshots to assist in explanations
Resizing some assets before upload
Merge branch 'days/11-async-testing'