Update Dockerfile

Dockerfile

@@ -74,6 +74,8 @@ RUN pyenv install $PYTHON_VERSION && \
     pyenv rehash && \
     pip install --no-cache-dir -U pip setuptools wheel
 
+RUN python -m nltk.downloader averaged_perceptron_tagger
+
 COPY --chown=user:user ./seamless_server ./seamless_server
 # change dir since pip needs to seed whl folder
 RUN cd seamless_server && \