Fix for junit fuilure message

Issue was mentioned here:
https://groups.google.com/forum/?hl=en&fromgroups=#!topic/scalatest-users/4rvEBV5PTsQ

Note:
- I didn't yet understand what is the better way to compile project. So I checked the fix in sandbox, and I assume some imports may be missed, hope not.
- @bvenners, I had to change case class access for testing purpose, but in general I'd like to make this reporter more public. I don't see reasons why is it private, with plenty private methods. Idea to make it more extensible.