Create jovyan in Dockerfile, reset UID at startup

… but install kernel specs global to avoid problems when switching NB_UID

Contribution (c) Copyright IBM Corp. 2015

Contribution (c) Copyright IBM Corp. 2015

* Create user jovyan with UID=1000 in the default users group in the Dockerfile
* Set group ownership of user home and conda to root to avoid 'users' group from host access when mounted
* Set stick bit on both paths so root owns subdirs too
* Change jovyan UID if NB_UID is specified and is not the default 1000

Contribution (c) Copyright IBM Corp. 2015

Add user in script + fixes

Contribution (c) Copyright IBM Corp. 2015

* Only create jovyan and set perms if user does not exist
* Allow docker host mount for NB_WORK: copy skel files if useradd fails because home dir already exists

Contribution (c) Copyright IBM Corp. 2015

* Always remain as root during install
* Put kernel specs in system path, not user home
* Create user work directory at startup
* Note this is in 4.0 and up images, not 3.2

Contribution (c) Copyright IBM Corp. 2015

Used to relaunch notebook and collect logging data.

Provides ability to specify NB_USER and NB_UID at docker run time rather than build time.

Updates to nymoorland datascience-notebook stack

Prevent r-irkernel from downgrading to ipython 3.2.1

Force irkernel to install without deps, then install the irkernel deps

Contribution (c) IBM Corp. 2015

* Merge 4.0.x branch
* Rejigger Dockerfiles to build from minimal-notebook:latest

Upgrade to Jupyter Notebook 4.0

* 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

Add a Gitter chat badge to README.md

Allow notebook patch release to vary