Update
* New models including `tomotopy.CTModel` and `tomotopy.SLDAModel` were added into the package.
* A new parameter option `rm_top` was added for all topic models.
Bug Fixed
* The problems in `save` and `load` method for `PAModel` and `HPAModel` were fixed.
* An occassional crash in loading `HDPModel` was fixed.
* The problem that `ll_per_word` was calculated incorrectly when `min_cf` > 0 was fixed.