Fix #248, added feature scaling, and a unit test. Consolidated remove NaN transformer to test_dataframe_transformers.py.
Fix #248, added feature scaling, and a unit test. Consolidated remove NaN transformer to test_dataframe_transformers.py.

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