Add flake8-import-order

.travis.yml

@@ -20,7 +20,7 @@ install:
 # Python
 - pip freeze
 - pip install -r monkey/monkey_island/requirements.txt  # for unit tests
-- pip install flake8 pytest dlint  # for next stages
+- pip install flake8 pytest dlint flake8-import-order # for next stages
 - pip install coverage  # for code coverage
 - pip install -r monkey/infection_monkey/requirements.txt  # for unit tests
 - pip install pipdeptree