0.5.0

• Now tomotopy.PAModel.infer returns both topic distribution nd sub-topic distribution.
• New methods get_sub_topics and get_sub_topic_dist were added into tomotopy.Document. (for PAModel)
• New parameter parallel was added for tomotopy.LDAModel.train and tomotopy.LDAModel.infer method. You can select parallelism algorithm by changing this parameter.
• tomotopy.ParallelScheme.PARTITION, a new algorithm, was added. It works efficiently when the number of workers is large, the number of topics or the size of vocabulary is big.
• A bug where rm_top didn't work at min_cf < 2 was fixed.