Add travis, npm badges
Add travis, npm badges

immersive-web/webvr-polyfill,marciot/webvr-polyfill,jsantell/webvr-polyfill,borismus/webvr-polyfill,jsantell/webvr-polyfill,marciot/webvr-polyfill,borismus/webvr-polyfill,immersive-web/webvr-polyfill