Open bucket asynchronously?

[yhpark]

https://github.com/ReactiveCouchbase/reactivecouchbase-rs-core/blob/master/src/main/scala/org/reactivecouchbase/rs/scaladsl/Bucket.scala#L81
(openBucket is blocking)

Currently the ReactiveCouchbase.bucket(~) method is a blocking call which is not something one would expect since all blocking operations are supposedly dealt with asynchronously.
Since Bucket instances are cached, blocking only happens when a bucket is opened for the first time.