Copied ch07/extract_features.py to ch08/
Copied ch07/extract_features.py to ch08/

naoyak/Agile_Data_Code_2,naoyak/Agile_Data_Code_2,naoyak/Agile_Data_Code_2,rjurney/Agile_Data_Code_2,rjurney/Agile_Data_Code_2,rjurney/Agile_Data_Code_2,rjurney/Agile_Data_Code_2,naoyak/Agile_Data_Code_2