Create DMG installer from APP.

Create DMG.md

1. Install node-appdmg.
2. Run with the bare minimum specs below.

{
	"title" : "PRODUCT_NAME",
	"window" :
	{
		"size" :
		{
			"width" : 512,
			"height" : 512
		}
	},
	"contents":
	[
		{
			"x": 256,
			"y": 256,
			"type": "file",
			"path": "PRODUCT_NAME.app"
		}
	]
}