add note to users about

[tunnckoCore]

That they should include Promise implementation to letta (follow the docs how you can do it) if they are on old environment or to install bluebird as dependency/devDependency, otherwise this package will throw - won't return promise.

It's because the changes to native-or-another@4. It's intentional, because in most of the cases it won't be needed. Bluebird is removed as dependecy from native-or-another, because it is huge dep - and because it was included in the bundle anyway even if you are on env that support native Promise and that's not logical.