release 0.12.1

Fixes issue with reassembling metadata

Update version to 0.12.1-RC1

release version

Adds specific requestChannel(Payload, Publisher<Payload>) (rsocket#572)

* optimize request channel to let you peak at the first item in the requestChannel

Signed-off-by: Robert Roeser <[email protected]>

* updated javadoc

Signed-off-by: Robert Roeser <[email protected]>

* updates

Signed-off-by: Robert Roeser <[email protected]>

* call requestChannelWith 2 arguments

Signed-off-by: Robert Roeser <[email protected]>

update version

Replace for loops with forEach in RSocketClient/Server to fix non-det…

…erministic behavior (rsocket#556)

Signed-off-by: Ryland Degnan <[email protected]>

Merge pull request rsocket#553 from robertroeser/perfTesting2

More performance improvements

Merge pull request rsocket#546 from rsocket/0.11.9-plus-stream-fix

0.11.9 plus stream fix

enable artifacts overriding

Signed-off-by: Oleh Dokuka <[email protected]>