[Example App] stress testing

[jessesquires]

Do more with the example app.

It would be great to have some kind of automation like the IGListKit "stress test". We could also run this as part of the UI Test suite.

Initial steps

• Introduce a new NumberModel. Similar to the existing ColorModel but it just wraps an Int. The motivation here is to be able to easily generate very large data sets. (And keep things simple and easy.)
• Add a new section with NumberModel objects to the existing views (just have like 0 to 9 or something small)

Later steps

• In a new tab in the example app, generate thousands of NumberModel items
• Implement some automation to shuffle them around (like the existing views, but automatic)

Other ideas (for later)

• Shuffle/Add/Remove items
• Shuffle/Add/Remove sections