update nbdime to 2.1.x

Author: blue-moose

jupyter-all-spark/Dockerfile

@@ -13,7 +13,7 @@ RUN apt-get update && \
 
 USER $NB_UID
 
-RUN pip install jupyterlab-code-formatter==1.3.* autopep8==1.5.* isort==4.3.* nbdime==2.0.* && \
+RUN pip install jupyterlab-code-formatter==1.3.* autopep8==1.5.* isort==4.3.* nbdime==2.1.* && \
     jupyter labextension install @ryantam626/jupyterlab_code_formatter@^v1.3.6 --no-build && \
     jupyter labextension install @jupyterlab/toc@^v3.0.0 --no-build && \
     jupyter labextension install jupyterlab-python-file@^v0.4.0 --no-build && \