Created by: kudep
Short list of changes:
- added a trainable ELMo model
- added saving a ELMo model to a hdf5 file
- added wrapping a ELMo model to a tf_hub module
- added a reader and iterator for large datasetes
- added a utf8 char encoder. It is originally based on
https://github.com/allenai/bilm-tf/blob/master/bilm/data.py