Allow overriding of recipients when using in staging environment

[davidlibrera]

In one of our staging environment we're working using real addresses and we should avoid sending them emails.
In ruby we usually use gems like RecipientInterceptor that allow to override all recipients (to, cc and bcc) with a custom list of addresses and setting the original ones in headers.

We have a PR ready that includes a new adapter RecipientReplacerAdapter that wraps the real adapter replacing all addresses.

config :my_app, MyApp.Mailer,
  adapter: Bamboo.RecipientReplacerAdapter,
  inner_adapter: Bamboo.SendGridAdapter,
  recipient_replacements: ["user-1@example.com", "user-2@example.com],
  ...

Could it be an interesting feature?

master...leanpanda-com:master

[maartenvanvliet]

A feature to handle use cases such as these is already being worked on 😀

See: #591

[davidlibrera]

Sorry, I've looked in Iusses and not in existing PRs