Merge pull request #986 from consideRatio/maintenance-bump-of-ubuntu

Bump Ubuntu 18.04 to latest build

Author: minrk

base-notebook/Dockerfile

@@ -1,9 +1,9 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 
-# Ubuntu 18.04 (bionic) from 2019-10-29
-# https://github.com/tianon/docker-brew-ubuntu-core/commit/d4313e13366d24a97bd178db4450f63e221803f1
-ARG BASE_CONTAINER=ubuntu:bionic-20191029@sha256:6e9f67fa63b0323e9a1e587fd71c561ba48a034504fb804fd26fd8800039835d
+# Ubuntu 18.04 (bionic)
+# https://hub.docker.com/_/ubuntu/?tab=tags&name=bionic
+ARG BASE_CONTAINER=ubuntu:bionic-20200112@sha256:bc025862c3e8ec4a8754ea4756e33da6c41cba38330d7e324abd25c8e0b93300
 FROM $BASE_CONTAINER
 
 LABEL maintainer="Jupyter Project <[email protected]>"