OpenNMT-tf 2.6.0

OpenNMT-tf 2.6.0

New features

• Multiple training files can be configured in train_features_file/train_labels_file, and train_files_weights optionally assign a weight to each file (see Data section in the documentation)
• Support exporting compatible models to CTranslate2 format (see export_format option)
• moving_average_decay training parameter to enable exponential moving average of the model variables

Fixes and improvements

• Fix error when starting a language model training
• Use tf.keras.layers.LayerNormalization instead of custom implementation for improved efficiency
• Fix possible duplicate call to checkpoint saving at the end of the training
• Ignore BLEU evaluation warning when run on tokenized data (which also caused duplicated logs for the rest of the training)
• Improve accuracy of reported prediction time by ignoring the initial graph construction