Force HTTPS everywhere.
Force HTTPS everywhere.

Use Rails-provided config.force_ssl to redirect to the HTTPS version
whenever the HTTP version is hit.

Tested on staging environment, also pushed to production and confirmed
it works there, behind Cloudflare SSL in "Force" mode.

For the production instance, confirmed that the http://vimgolf.herokuapp.com
endpoint which hits Heroku directly (not via Cloudflare SSL) now properly
redirects to HTTPS as expected.

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