Fix flake8 errors.
Fix flake8 errors.

sampsyo/beets,SusannaMaria/beets,beetbox/beets,shamangeorge/beets,jackwilsdon/beets,jackwilsdon/beets,jackwilsdon/beets,ibmibmibm/beets,shamangeorge/beets,beetbox/beets,sampsyo/beets,sampsyo/beets,jackwilsdon/beets,SusannaMaria/beets,shamangeorge/beets,beetbox/beets,SusannaMaria/beets,SusannaMaria/beets,ibmibmibm/beets,beetbox/beets,shamangeorge/beets,sampsyo/beets,ibmibmibm/beets,ibmibmibm/beets