Modify keras batch normalization to support 2D input (#1223)
Modify keras batch normalization to support 2D input (#1223)

* keras batch normalization

* update

* update with comments

* update with comments

* update for test case

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