message: travis: Pin flake8 version to 3.5.0
diff: @@ -148,7 +148,7 @@ jobs:
  language: python
  python: '3.6'
  install:
  - - travis_retry pip install flake8
  + - travis_retry pip install flake8==3.5.0
  before_script:
  - git fetch --unshallow
  script:
  