Merge pull request #349 from tony/flake8-ci

add flake8 to travis-ci

Author: tony

.travis.yml

@@ -28,7 +28,7 @@ before_install:
   - export PIP_USE_MIRRORS=true
   - pip install --upgrade pytest  # https://github.com/travis-ci/travis-ci/issues/4873
   - pip install --upgrade pip wheel virtualenv setuptools
-  - pip install pytest-cov coverage codecov
+  - pip install pytest-cov coverage codecov flake8
 install:
   - pip install -e .
   - pip install -r requirements/test.txt
@@ -41,7 +41,9 @@ before_script:
   - export PATH=$HOME/tmux/bin:$PATH
   - cd ..
   - tmux -V
-script: py.test --cov
+script:
+  - py.test --cov
+  - make flake8
 addons:
   apt:
     packages: