Adds functionality to log users out automatically after 15 minutes without activity (clicking, typing, or new requests).
Users are redirected to a relogin page. If they re-enter their password on this page, they'll be directed back to the page they were on before their session expired.
If user is on the patient details page and gets automatically logged out before saving the form, store their form data as JSON in a temp table and repopulate the form if the user logs back in. The user still has to save the form to permanently save that data (otherwise we'd run the risk of auto-saving data that wouldn't have passed validation).
To do: add the temporary saving of form data to other forms (prescreening and entering screening results) and properly style the relogin page.
Also includes some Dockerfile and Procfile updates for Aptible.