MAINT: pep8 fix and remove unused import
MAINT: pep8 fix and remove unused import

grlee77/pywt,eriol/pywt,kwohlfahrt/pywt,eriol/pywt,rgommers/pywt,michelp/pywt,kwohlfahrt/pywt,michelp/pywt,rgommers/pywt,rgommers/pywt,rgommers/pywt,eriol/pywt,michelp/pywt,PyWavelets/pywt,grlee77/pywt,kwohlfahrt/pywt,PyWavelets/pywt