fixes Flake8 warnings
fixes Flake8 warnings

TGAC/earlham-galaxytools,TGAC/earlham-galaxytools,anilthanki/tgac-galaxytools,TGAC/earlham-galaxytools,anilthanki/tgac-galaxytools,TGAC/earlham-galaxytools,anilthanki/tgac-galaxytools,anilthanki/tgac-galaxytools,anilthanki/tgac-galaxytools,TGAC/earlham-galaxytools