message: Update circle CI test image
diff: @@ -43,7 +43,9 @@ jobs:
  # feature, as documented in https://circleci.com/docs/2.0/building-docker-images/#separation-of-environments
  # As a consequence, we cannot use the circleci CLI for this job because "You cannot use the machine
  # executor in local jobs." (https://circleci.com/docs/2.0/local-cli/#limitations-of-running-jobs-locally)
  - image: ubuntu-1604:201903-01
  + #
  + # Available images: https://circleci.com/docs/2.0/configuration-reference/#available-machine-images
  + image: ubuntu-1604:202004-01
  steps:
  - checkout
  - run: # start early for less wait time below
  