update flake8 in .travis.yml
@@ -54,7 +54,7 @@ install:
- ./elasticsearch-${ES_VERSION}/bin/elasticsearch &
- cd $PROJECT_DIR
- travis_retry pip install --upgrade pip
- - travis_retry pip install flake8==3.0.4 --force-reinstall --upgrade
+ - travis_retry pip install flake8==3.8.3 --force-reinstall --upgrade
- travis_retry pip install -r dev-requirements.txt
- travis_retry pip install .
