Remove commented python3 ipykernel install line (#1986)
Remove commented python3 ipykernel install line (#1986)

The line `#python -m ipykernel install && \` was mistakenly left in the Dockerfile. Since things work with it commented, I'm just going to remove it.

For the record, the only change I observed when uncommenting it was running

    !jupyter kernelspec list

in the python 2 kernel went from returning:

    Available kernels:
      python2    /usr/local/envs/py2env/share/jupyter/kernels/python2

to returning:

    Available kernels:
      python2    /usr/local/envs/py2env/share/jupyter/kernels/python2
      python3    /usr/local/share/jupyter/kernels/python3
parthea/datalab,parthea/datalab,googledatalab/datalab,parthea/datalab,googledatalab/datalab,parthea/datalab,parthea/datalab,parthea/datalab,googledatalab/datalab,googledatalab/datalab,googledatalab/datalab,googledatalab/datalab