change default filters to 0.2Hz and 20Hz, as per UKB working group meeting discussion
change default filters to 0.2Hz and 20Hz, as per UKB working group meeting discussion

aidendoherty/biobankAccelerometerAnalysis,computationalEpidemiology/biobankAccelerometerAnalysis,computationalEpidemiology/biobankAccelerometerAnalysis,aidendoherty/biobankAccelerometerAnalysis