Make `ResultAsync.fromPromise` and `ResultAsync.fromSafePromise` less strict!

Thanks to @bhvngt for this submission.

ResultAsync.fromPromise and ResultAsync.fromSafePromise are now able to accept anything that implements the PromiseLike interface - in other words; anything that is "thenable". This includes objects such as Bluebird Promises and any other non-native promise-like object!