Add TFPredictor (#638)
Add TFPredictor (#638)

* add tf predictor

* move batch size to dataset

* support batch size

* add evaluate example

* fix api

* fix style

* fix styl

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