Travis-ci: workaround to test gcc 4.8, 4.9, 5.0 and Nodejs 4, 5, 6
Travis-ci: workaround to test gcc 4.8, 4.9, 5.0 and Nodejs 4, 5, 6

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