Notify the user that tests have passed or failed

[orta]

I don't have too strong of an opinion here.

To start with maybe just a green . for a pass, and then ideally - something like RSpec's output for a fail.

I would expect that the logs would show up in Xcode ATM. On the long term they will not though, so there may need to be a way to pipe all output. If so, we may want to consider XCPretty, or whatever @KrauseFx has been cooking up lately.

[KrauseFx]

I've been working on trainer, which parses the resulting plist files instead of the xcodebuild output. Both are valid approached with different advantages 👍