test: add tests for console.[info|error|warn]

Just copied the basic tests for log, as they're all the same thing
as log in either stdout or stderr. Cleaned that up a bit.

Also const-ified.

PR-URL: https://github.com/nodejs/node/pull/6538


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: James M Snell <jasnell@gmail.com>