Check QA: add tasks to run flake8 to tox/travis

Also fix any current issues.
Merge pull request #153 from blueyed/checkqa

Check QA: add flake8 to tox/travis
Remove the conftest.py PYTHONPATH hack from FAQ. Refs #23.
Added a note about pytest-pythonpath to FAQ, thanks to Alexander
Schepanovski for the suggestion. Refs #23.
Server static files live_server fixture and Django1.7

fixes #120