Version bump

package.json

 {
   "name": "encantar-js",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "description": "GPU-accelerated Augmented Reality for the web",
   "author": "Alexandre Martins <alemartf@gmail.com> (https://github.com/alemart)",
   "homepage": "https://github.com/alemart/encantar-js",