Merge branch 'django' into jupyterhub_2019

The branc cannot run job, this looks related to code already updated in the django branch.
Status Job ID Name Coverage
  Build
failed #303933
bootstrap

00:00:01

 
Name Stage Failure
failed
bootstrap Build
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false

WARNING: No swap limit support
$ apk update
bash: line 75: apk: command not found
ERROR: Job failed: exit status 1