Update spacy_tagger.py
Update spacy_tagger.py

But still does not work, it crashes with:

```python
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/thinc/extra/_vendorized/keras_generic_utils.py", line 114, in update
    numdigits = int(np.floor(np.log10(self.target))) + 1
ValueError: cannot convert float NaN to integer
```
explosion/thinc,explosion/thinc,spacy-io/thinc,spacy-io/thinc,spacy-io/thinc,explosion/thinc,explosion/thinc