Merge branch 'master' into yak-shaving
Increase landscape.io health

By
- getting rid of unused and wrong imports
- fixing the most easy `pep8` errors
- consolidating tabs with spaces
Rewording some things
We looped unnecessarily complicated

Replacing all "SelectedExperiments" in the main loop by "Counter" makes
things a bit nicer to look at.
Merge branch 'yak-shaving'