Feature/test web view

~~Not quite ready for a merge - but wanted to discuss.~~ Ready to merge!

This is in reference to
calabash/calabash-ios#41

This doesn't fix that bug, but it introduces a rudimentary regression test for WebView navigation. Since it's not high priority, I'm going to just jot down my notes and move on.

~~Oddly the test passes~~ (edit: got the test to fail as expected in 9c32887), but I can't see the secret message displayed when I visually inspect the simulator.