Add example with mixed cell types

[dcaunt]

Pull request checklist

• All tests pass. Demo project builds and runs.
• I have resolved any merge conflicts.
• I have followed the coding style, and reviewed the contributing guidelines.

This fixes issue #57

What's in this pull request?

An example implementing the approach discussed in #57

Let me know if you'd like to revise the example in any way or if there are any issues.

[codecov-io]

Current coverage is 89.04% (diff: 100%)

Merging #58 into develop will not change coverage

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  Files             9          9          
  Lines           365        365          
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
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  Hits            325        325          
  Misses           40         40          
  Partials          0          0          

Powered by Codecov. Last update 66adb74...1f5798a

[jessesquires]

remove this? 😄

[dcaunt]

Oh haha, will do

[jessesquires]

Thanks so much @dcaunt ! This is awesome ✨ 🎉

[jessesquires]

1 small comment. Looks like some left over debugging code?

[jessesquires]

After we merge this, would you be interested helping with the following:

1. merging develop into swift2.3, migrate, submit PR
2. then merging swift2.3 into swift3.0, migrate, submit PR

No pressure if you don't have time, or don't want to! 😊 I can take care of this. Just wanted to ask.

[dcaunt]

Yes, I can migrate this PR to the other Swift versions, it's not much work :)

[jessesquires]

Thanks @dcaunt ! 🎉