While all is fine in Fedora and all packages needed to run the JupyROOT
notebook are available there, this is not true for EPEL.

Hopefully the ipython/jupyter stack will at some point be available in
EPEL too, but at this point in time it is not.

However, it is possible to work around this issue using a python
virtual environment.

First, install the required root packages (as root):

$ yum install root root-notebook python3-jupyroot

Then return to your non-root user and create a python3 virtual
environment:

$ python3 -m venv ~/jupyter-env

Activate the environment:

$ . ~/jupyter-env/bin/activate

Then install the missing packages in the virtual environment using pip:

$ pip install notebook metakernel

Then start the root notebook:

$ PYTHONPATH=~/jupyter-env/lib/python3.6/site-packages root --notebook

And that is it.

If you want to start it again and you haven't removed the virtual
environment, only two of the steps are necessary:

$ . ~/jupyter-env/bin/activate
$ PYTHONPATH=~/jupyter-env/lib/python3.6/site-packages root --notebook