Add parent controller option

[yenshirak]

I think this makes sense because it follows the same pattern as parent_mailer. It is possible to extract the base controller logic into a concern and include that in a custom Passwordless controller but using an option would be more convenient.

[mikker]

Do you have a need for this in your app(s)?

[yenshirak]

Yes. It's used on the admin interface so the parent should be the admin base controller.

[mikker]

Got it. Thanks!