Add zero_grad_parameters and update_parameters methods (#1018)
Add zero_grad_parameters and update_parameters methods (#1018)

* Add zero_grad_parameters and update_parameters methods

* revert

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