Move repo icon.

Author: tehvgg

icon.png renamed to assets/icon.png

@@ -16,7 +16,7 @@
   "contributors": [
     "Patrick McGuckin <patrick@gskinner.com> (https://github.com/tehvgg)"
   ],
-  "logo": "icon.png",
+  "logo": "assets/icon.png",
   "repository": {
     "type": "git",
     "url": "https://github.com/createjs/build.git"