message: Add missing library in Dockerfile
  The local Dockerfile does not have all the dependencies for running the exercise notebooks in udacity assignments.
diff: @@ -8,7 +8,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
  apt-get clean && \
  rm -rf /var/lib/apt/lists/*
  -RUN pip install scikit-learn pyreadline Pillow
  +RUN pip install scikit-learn pyreadline Pillow imageio
  RUN rm -rf /notebooks/*
  ADD *.ipynb /notebooks/
  WORKDIR /notebooks
  