flake8-print is a flake8 plugin that checks for `print()` statements in
Python files.
This should save us having to manually spot these when reviewing pull
requests.
The `--enable=T` flag needs to be set until this bug is fixed:
https://github.com/JBKahn/flake8-print/issues/27
flask-script has been deprecated by the internal flask.cli module, but
making this carries a few changes with it
* you should add FLASK_APP=application.py and FLASK_DEBUG=1 to your
environment.sh.
* instead of using `python app.py runserver`, now you must run
`flask run -p 6012`. The -p command is important - the port must be
set before the config is loaded, so that it can live reload nicely.
(https://github.com/pallets/flask/issues/2113#issuecomment-268014481)
* find available commands by just running `flask`.
* run them using flask. eg `flask list_routes`
* define new tasks by giving them the decorator
`@app.cli.command('task-name')`. Task name isn't needed if it's just
the same as the function name. Alternatively, if app isn't available
in the current scope, you can invoke the decorator directly, as seen
in app/commands.py
