update ops in trainer for batch norm
update ops in trainer for batch norm

juliakreutzer/bandit-neuralmonkey,juliakreutzer/bandit-neuralmonkey,juliakreutzer/bandit-neuralmonkey,ufal/neuralmonkey,ufal/neuralmonkey,juliakreutzer/bandit-neuralmonkey,juliakreutzer/bandit-neuralmonkey,ufal/neuralmonkey,ufal/neuralmonkey,ufal/neuralmonkey