Scala test fw

First attempt to use the inhouse Scala testing framework with one test for checking the picture overlay functionality. Keep in mind that I am a beginner Scala dev so code will likely look very "Javaish"
If this `existsAndDisplayed` was returning an `Option[String]`, you would not have to `catch` anything here and would be able to use `isDefined` or pattern match on it to log out the error. You could also use a `List`.