In `12.0.0` (#123) it could be useful to add the [promise/catch-or-return](https://github.com/xjamundx/eslint-plugin-promise/blob/master/docs/rules/catch-or-return.md) to help people catch the cases where one might have missed a `catch()` or `return`? Especially as `unhandledRejection` is [deprecated](https://nodejs.org/dist/latest-v8.x/docs/api/deprecations.html#deprecations_dep0018_unhandled_promise_rejections) and will start throwing. Thoughts?