Enable Python style check (#133)
Enable Python style check (#133)

* add style check

* fix all style errors

* fix style

* update utils

* update

* fixc

* update

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