update imports; make unit tests pass; add travis config

If the runner needs the Stream value from the config, it should not get
it from the reporter. It is better to keep a copy of the value in the
runner itself to make the communication between runner and reporter only
one-direction.

The logger and the reporter should be configured independently.
We can do many improvements in the logger, but for now this change
preserves the public interfaces, keeps all the tests passing and
lets us focus on improving the reporter first.