indicate whether need access token in each methods.

[Toshihiro Yagi]

Add interface for each method.
The interface is divided as follows.

interface TimelinesInterface {
  interface Public {
     // ...
  }
  interface AuthRequired {
    // ...
  }
}

[Toshihiro Yagi]

You can see if authentication is needed with before_action.
https://github.com/tootsuite/mastodon/blob/master/app/controllers/api/v1/timelines_controller.rb#L4