Devel inria

We added a new Ros audio message type that can convey the six audio channels that the respeaker device is able to provide (4 raw microphone capture + 2 processed audio outputs). We added a modified version of the respeaker node (respeaker_multi) that publishes audio messages using the above message type. We would like to make this version available for everybody in the project, so that they can access to the four raw audio microphone with ros.