Third release
This third release comprise the following updates:
- added the two new pre-trained model from Google: `bert-large-cased` and `bert-multilingual-cased`,
- added a model for token-level classification: `BertForTokenClassification`,
- added tests for every model class, with and without labels,
- fixed tokenizer loading function `BertTokenizer.from_pretrained()` when loading from a directory containing a pretrained model,
- fixed typos in model docstrings and completed the docstrings,
- improved examples (added `do_lower_case`arguments).
