Remove landscape failures

[syre]

PR for removing some of the code health failures from Landscape:

• use new-style classes
• specify string format arguments as logging function parameters
• remove deprecated load_stylesheet_pyqt5 and replace with load_stylesheet

[coveralls]

Coverage remained the same at 24.981% when pulling 0009481 on syre:remove-landscape-failures into db3ba28 on pynocchio:develop.

[syre]

@mstuttgart i believe the logging call are correct as this is the way to do string substitution in logging (as argument) https://docs.python.org/3/library/logging.html#logging.Logger.debug

[mstuttgart]

Sorry @syre . You're right: https://fangpenlin.com/posts/2012/08/26/good-logging-practice-in-python/

[mstuttgart]

Greate work @syre . Please fix the flake8 errors: https://travis-ci.org/pynocchio/pynocchio/jobs/439123980#L743

[syre]

Thanks @mstuttgart i have done so now