anchor.diff:  
   RUN conda config --add channels brian-team
   # TODO: Update ipywidgets to 5.1*
  +# conda install -c conda-forge lmfit=0.9.5
   # Install Python 3 packages
   RUN conda install --quiet --yes \
       'ipywidgets=4.1*' \
  
positive.code:     'numexpr=2.5*' \
      'matplotlib=1.5*' \
      'scipy=0.17*' \
      'lmfit=0.9*' \
      'seaborn=0.7*' \
      'sympy=1.0*' \
      'cython=0.24*' \
  
negative.code:     'numexpr=2.5*' \
      'matplotlib=1.5*' \
      'scipy=0.17*' \
      #'lmfit=0.9*' \
      'seaborn=0.7*' \
      'sympy=1.0*' \
      'cython=0.24*' \
  