Fix in array indexing in vocabulary
Fix in array indexing in vocabulary

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