RAC-6393: enable travisci nodejs6/8 gate
RAC-6393: enable travisci nodejs6/8 gate

lanchongyizu/on-http,RackHD/on-http,lanchongyizu/on-http,RackHD/on-http,lanchongyizu/on-http,lanchongyizu/on-http,RackHD/on-http,RackHD/on-http