Add dependencies and finish the py-tornado package.

This adds the following packages:

 py-backports-shutil-get-terminal-size  py-nbformat
 py-backports-ssl-match-hostname        py-pathlib2
 py-entrypoints                         py-pickleshare
 py-futures                             py-pip
 py-ipykernel                           py-prompt-toolkit
 py-ipython-genutils                    py-ptyprocess
 py-ipywidgets                          py-simplegeneric
 py-jupyter-client                      py-singledispatch
 py-jupyter-console                     py-terminado
 py-jupyter-core                        py-traitlets
 py-jupyter-notebook                    py-wcwidth
 py-monotonic                           py-widgetsnbextension
 py-nbconvert