Add main file to package.json.

Author: blueimp

package.json

@@ -30,6 +30,7 @@
     "type": "git",
     "url": "git://github.com/blueimp/JavaScript-Load-Image.git"
   },
+  "license": "MIT",
   "devDependencies": {
     "phantomjs-prebuilt": "2.1.13",
     "mocha-phantomjs-core": "1.3.1",
@@ -45,5 +46,5 @@
     "version": "npm run build && git add -A js",
     "postversion": "git push --tags origin master master:gh-pages && npm publish"
   },
-  "license": "MIT"
+  "main": "js/load-image.js"
 }