fixed bug with dropna in __init__ method of DevelopSupervisedModel
fixed bug with dropna in __init__ method of DevelopSupervisedModel

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