.travis.yml: add Node 12
.travis.yml: add Node 12

versatica/mediasoup,versatica/mediasoup,versatica/mediasoup,versatica/mediasoup,versatica/mediasoup,ibc/MediaSoup,ibc/MediaSoup,ibc/MediaSoup,versatica/mediasoup,versatica/mediasoup,versatica/mediasoup,versatica/mediasoup