message: Use ubuntu 18.04 docker image that provides clang-format-8 and python3.7
diff: @@ -2,7 +2,7 @@ version: 2.1
  jobs:
  tests:
  docker:
  - - image: circleci/python:3.7
  + - image: ubuntu:18.04
  steps:
  - checkout
  @@ -14,10 +14,10 @@ jobs:
  - run:
  name: install dependencies
  command: |
  + sudo apt-get update && sudo apt-get install -y clang-format-8 python3.7
  python3 -m venv venv
  . venv/bin/activate
  ./scripts/setup.sh
  - sudo apt-get update && sudo apt-get install -y clang-format-8
  - save_cache:
  paths:
  