test examples after they've been packaged

I also changed Jenkins to reflect this change in order:

![image](https://cloud.githubusercontent.com/assets/474794/4961756/bc06a64a-66d2-11e4-9d8d-8b21cea33df2.png)
This isn't run from a directory containing realm-cocoa's build.sh. `unzip realm-cocoa-*.zip` should work.