* Bump `base-notebook`
	* OS version
	* `jupyterlab`
* Bump `scipy-notebook`
	* `beautifulsoup4`
	* `cloudpickle`
	* `dask`
	* `numba`
	* `xlrd`: version specified (it was not the case)
* Bump `datascience-notebook`
	* `r-devtools`
	* `r-forecast`
	* Julia version
	* Test added to check if Julia is correctly installed (`julia --version`)
	* Note: A new version of `r-base` is out `4.0.0` however it cannot be installed yet since dependencies with other packages cannot be resolved.
* Bump `r-notebook`
	* Same as `datascience-notebook` except Julia.
* Bump `all-spark-notebook`
	* `r-sparklyr`