add nbdime to jupyterlab

science/Dockerfile

@@ -13,7 +13,8 @@ RUN conda env update -n base -f /environments/environment.yml && \
     conda clean -tipsy
 
 # Enable jupyter extension
-RUN jupyter labextension install @pyviz/jupyterlab_pyviz
+RUN jupyter labextension install @pyviz/jupyterlab_pyviz && \
+    jupyter labextension install nbdime-jupyterlab
 
 # Fix permissions (required when following the base image)
 RUN fix-permissions $HOME && \

science/environment.yml

 name: science
 dependencies:
+  # misc tools
+  - conda-forge::nbdime=1.0.1
+
   # main scientific packages
   - conda-forge::scipy=1.1.0
   - conda-forge::numpy=1.14.5