added feature scaling, under/over sampling, impact coding
added feature scaling, under/over sampling, impact coding

HealthCatalyst/healthcareai-py,jpo/healthcareai-py,jpo/healthcareai-py,mxlei01/healthcareai-py,HealthCatalystSLC/healthcareai-py,mxlei01/healthcareai-py,HealthCatalyst/healthcareai-py,HealthCatalystSLC/healthcareai-py