* update to 1.6 APIs and fix bugs with tensorboard. (#3663)

* ini commit for deepvoice, add tensorboard to requirements

* fix urls for code we adapted from

* fix makedirs for python2, fix README

* fix open with encoding for python2 compatability

* fix python2's str(), use encode for unicode, and str() for int

* fix python2 encoding issue, add model architecture and project structure for README

* add model structure, add explanation for hyperparameter priority order.

* fix repitiio n in README_cn, and reorder that in README

* README update; fix integer division issues for python2 compatability

* fix data type for input data, specifier the int type as np.int64 to be platform agnostic

* fix README for preprocess.py, use io.open instead of open for python2 compatability.

* update commanline options, use new save/load API

* fix IO conflict bug for data parallel training

* only construct summary writer in process 0 to further avoid conflict

* update details about checkpoint in README (#3673)

* ini commit for deepvoice, add tensorboard to requirements

* fix urls for code we adapted from

* fix makedirs for python2, fix README

* fix open with encoding for python2 compatability

* fix python2's str(), use encode for unicode, and str() for int

* fix python2 encoding issue, add model architecture and project structure for README

* add model structure, add explanation for hyperparameter priority order.

* fix repitiio n in README_cn, and reorder that in README

* README update; fix integer division issues for python2 compatability

* fix data type for input data, specifier the int type as np.int64 to be platform agnostic

* fix README for preprocess.py, use io.open instead of open for python2 compatability.

* update commanline options, use new save/load API

* fix IO conflict bug for data parallel training

* only construct summary writer in process 0 to further avoid conflict

* fix typos and update details for checkpoints

* update installation guide

* ini commit for deepvoice, add tensorboard to requirements

* fix urls for code we adapted from

* fix makedirs for python2, fix README

* fix open with encoding for python2 compatability

* fix python2's str(), use encode for unicode, and str() for int

* fix python2 encoding issue, add model architecture and project structure for README

* add model structure, add explanation for hyperparameter priority order.