Flask warning when loading local webserver

[alykat]

Getting the following warning with a fresh dailygraphics install when starting up the the local webserver and on deploy:

(dg-test) MACHINE:dg-test ahurt$ fab app:2222
[localhost] local: gunicorn -b 0.0.0.0:2222 --timeout 3600 --reload app:wsgi_app
[2019-04-17 18:00:08 -0400] [34343] [INFO] Starting gunicorn 19.8.1
[2019-04-17 18:00:08 -0400] [34343] [INFO] Listening at: http://0.0.0.0:2222 (34343)
[2019-04-17 18:00:08 -0400] [34343] [INFO] Using worker: sync
[2019-04-17 18:00:08 -0400] [34346] [INFO] Booting worker with pid: 34346
/Users/ahurt/.virtualenvs/dg-test/lib/python2.7/site-packages/flask/sessions.py:111: UserWarning: The default 'SecureCookie.serialization_method' will change from pickle to json in version 1.0. To upgrade existing tokens, override 'unquote' to try pickle if json fails.
  return self.null_session_class()