- Bump root container version
- Bump  packages of
  - scipy-notebook
  - r-notebook
  - datascience-notebook
- add -y flag to jupyter lab commands in scipy-notebook
- Fix a bug in check outdated packages when packages installed through pip

Tring to swithch to the last bionic Travis build environment.
https://docs.travis-ci.com/user/reference/bionic/

Bump miniconda -> 4.8.2

recipe: dask

Co-Authored-By: Peter Parente <parente@gmail.com>

Using jupyter lab clean command instead of rm (#752)

include dvipng

Test packages

Fix #1041: Update JupyterLab start command

update jupyterlab and plotting extensions

Bump Ubuntu Base Image

Conda outdated package helper