Merge #447: pin flake8 version to avoid breaking compatibilities

77e8fa4 pin flak8 version to avoid breaking compatibilities (Gregory Sanders)

Pull request description:

  This happened upstream too.

Tree-SHA512: a6d05c86e1421c03ac38ee69c4b5ff7174d7c00b0c965fcd6016a9f9b94510e4a68dce162f4bb47a2ba5d624bfc33cc6ae53fc47264d98e117632f0a6a580bed

Author: instagibbs

.travis.yml

@@ -158,7 +158,7 @@ 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: