[REF] auto-fix conventions

From where does come this idea to put a blank line between the class and the docstring?
This is not what says the pep0257: http://legacy.python.org/dev/peps/pep-0257/

> * There's no blank line either before or after the docstring.

> Insert a blank line after all docstrings (one-line or multi-line) that document a class -- generally speaking, the class's methods are separated from each other by a single blank line, and the docstring needs to be offset from the first method by a blank line.