Add encoding while opening file for python3: master (#885)
Add encoding while opening file for python3: master (#885)

* add encoding for python3 while opening file

* add unittest

* style

intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL,yangw1234/BigDL