* Change minimal-notebook to install notebook=4.0*
* Change other Dockerfile to point to 4.0 Docker Hub tag (to be built)
* Change config and pem file paths for jupyter
* Install ipywidgets in all containers that have a Python stack
* Update all READMEs to describe v3.2 and v4.0 since Docker Hub only shows one README for all tags
Contribution (c) Copyright IBM Corp. 2015
