remove deprecation warning from pylint 1.0

In pylint > 1.0, there is a warning from using ParseableTextReporter. This will use the main TextReporter class, with the line_format set to be the same as the old ParseableTextReporter.

https://bitbucket.org/logilab/pylint/src/bdebb394a37ac7e18328a5f49124f44e8e11e82d/reporters/text.py?at=default#cl-68