OpenNMT-tf 2.28.0

New features

• Add initial_learning_rate parameter to the InvSqrtDecay schedule
• Add new arguments to the Transformer constructor:
  • mha_bias: to disable bias terms in the multi-head attention (as presented in the original paper)
  • output_layer_bias: to disable bias in the output linear layer

Fixes and improvements

• Fix incorrect dtype for SequenceRecordInputter length vector
• Fix rounding error when batching datasets which could make the number of tokens in a batch greater than the configured batch size
• Fix deprecation warning when using distutils.version.LooseVersion, use packaging.version.Version instead
• Make the length dimension unknown in the dataset used for batch size autotuning so that it matches the behavior in training
• Update SacreBLEU requirement to include new version 2.2