Update Dockerfile

Dockerfile

@@ -23,7 +23,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 ENV CONDA_DIR /opt/conda
 ENV PATH $CONDA_DIR/bin:$PATH
 
-RUN wget --quiet https://repo.anaconda.com/miniconda/Miniconda3-4.5.11-Linux-x86_64.sh -O ~/miniconda.sh && \
+RUN wget --quiet https://repo.anaconda.com/miniconda/Miniconda3-py37_4.8.2-Linux-x86_64.sh -O ~/miniconda.sh && \
     /bin/bash ~/miniconda.sh -b -p /opt/conda && \
     rm ~/miniconda.sh && \
     /opt/conda/bin/conda clean -tipsy && \
@@ -45,7 +45,7 @@ RUN useradd -m -s /bin/bash -N -u $NB_UID $NB_USER && \
 
 USER $NB_USER
 
-ARG python_version=3.6
+ARG python_version=3.7
 
 RUN conda config --append channels conda-forge
 RUN conda install -y python=${python_version} && \