installing packages via pipenv

```
$ pipenv install --skip-lock -r requirements.txt
$ pipenv install --skip-lock jupyterlab  
```

I was seeing some package errors if not using  --skip-lock ...
i.e. Could not find a version that matches matplotlib==2.2.2,==3.0.1,>=2.0.0 

And to create a env kernel named "network-env":

```
$ pipenv run python -m ipykernel install --user --name=network-env
```