travis add opencv 4.0.0 and 4.1.0 build
travis add opencv 4.0.0 and 4.1.0 build

justadudewhohacks/opencv4nodejs,justadudewhohacks/opencv4nodejs,justadudewhohacks/opencv4nodejs,justadudewhohacks/opencv4nodejs,justadudewhohacks/opencv4nodejs,justadudewhohacks/opencv4nodejs