inherit pyspark from scipy-notebook

removes duplicate installation of python 2 env and Python packages.

There are very few packages in scipy not in pyspark, so removing the duplicate seems valuable.

pyspark-notebook/Dockerfile

 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
-FROM jupyter/minimal-notebook
+FROM jupyter/scipy-notebook
 
 MAINTAINER Jupyter Project <jupyter@googlegroups.com>
 
@@ -40,44 +40,3 @@ ENV MESOS_NATIVE_LIBRARY /usr/local/lib/libmesos.so
 ENV SPARK_OPTS --driver-java-options=-Xms1024M --driver-java-options=-Xmx4096M --driver-java-options=-Dlog4j.logLevel=info
 
 USER $NB_USER
-
-# Install Python 3 packages
-RUN conda install --quiet --yes \
-    'ipywidgets=5.1*' \
-    'pandas=0.17*' \
-    'numexpr=2.5*' \
-    'matplotlib=1.5*' \
-    'scipy=0.17*' \
-    'seaborn=0.7*' \
-    'scikit-learn=0.17*' \
-    jq \
-    && conda clean -tipsy
-# Activate ipywidgets extension in the environment that runs the notebook server
-RUN jupyter nbextension enable --py widgetsnbextension --sys-prefix
-    
-# Install Python 2 packages and kernel spec
-RUN conda create --quiet --yes -p $CONDA_DIR/envs/python2 python=2.7 \
-    'ipython=4.2*' \
-    'ipywidgets=5.1*' \
-    'pandas=0.17*' \
-    'numexpr=2.5*' \
-    'matplotlib=1.5*' \
-    'scipy=0.17*' \
-    'seaborn=0.7*' \
-    'scikit-learn=0.17*' \
-    pyzmq \
-    && conda clean -tipsy
-# Add shortcuts to distinguish pip for python2 and python3 envs
-RUN ln -s $CONDA_DIR/envs/python2/bin/pip $CONDA_DIR/bin/pip2 && \
-    ln -s $CONDA_DIR/bin/pip $CONDA_DIR/bin/pip3
-
-# Install Python 2 kernel spec into the Python 3 conda environment which
-# runs the notebook server
-RUN bash -c '. activate python2 && \
-    python -m ipykernel.kernelspec --prefix=$CONDA_DIR && \
-    . deactivate'
-# Set PYSPARK_HOME in the python2 spec
-RUN jq --arg v "$CONDA_DIR/envs/python2/bin/python" \
-        '.["env"]["PYSPARK_PYTHON"]=$v' \
-        $CONDA_DIR/share/jupyter/kernels/python2/kernel.json > /tmp/kernel.json && \
-        mv /tmp/kernel.json $CONDA_DIR/share/jupyter/kernels/python2/kernel.json