SSL redirect:
* Move `:host` and `:port` options within `redirect: { … }`. Deprecate.
* Introduce `:status` and `:body` to customize the redirect response.
The 301 permanent default makes it difficult to test the redirect and
back out of it since browsers remember the 301. Test with a 302 or 307
instead, then switch to 301 once you're confident that all is well.
HTTP Strict Transport Security (HSTS):
* Shorter max-age. Shorten the default max-age from 1 year to 180 days,
the low end for https://www.ssllabs.com/ssltest/ grading and greater
than the 18-week minimum to qualify for browser preload lists.
* Disabling HSTS. Setting `hsts: false` now sets `hsts: { expires: 0 }`
instead of omitting the header. Omitting does nothing to disable HSTS
since browsers hang on to your previous settings until they expire.
Sending `{ hsts: { expires: 0 }}` flushes out old browser settings and
actually disables HSTS:
http://tools.ietf.org/html/rfc6797#section-6.1.1
* HSTS Preload. Introduce `preload: true` to set the `preload` flag,
indicating that your site may be included in browser preload lists,
including Chrome, Firefox, Safari, IE11, and Edge. Submit your site:
https://hstspreload.appspot.com
`ActionDispatch::SSL` changes headers to `Hash`.
So some headers will be broken if there are some middlewares
on ActionDispatch::SSL and if it uses `Rack::Utils::HeaderHash`.
Non-kwargs requests are deprecated now.
Guides are updated as well.
`post url, nil, nil, { a: 'b' }` doesn't make sense.
`post url, params: { y: x }, session: { a: 'b' }` would be an explicit way to do the same
