Since we version our asset filenames there’s no need for a browser to
ever fetch the same file twice. It should always cache fetch from its
own cache.
The accepted way to effect this behaviour is using the expires header,
which is what this argument to `WhiteNoise` does.
We're now running our app as a wsgi app locally, so don't need to
distinguish between the two processes by having wsgi and application.py
whitenoise just serves static files nicely - we don't lose anything
by doing that locally.
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
