Avoid using window in export

package.json

@@ -5,7 +5,7 @@
   "main": "dist/FileSaver.js",
   "module": "src/FileSaver.js",
   "files": [
-    "dist/FileSaver.min.js",
+    "dist/FileSaver.min.js"
   ],
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 0",

src/FileSaver.js

@@ -13,7 +13,7 @@
 
 /*! @source http://purl.eligrey.com/github/FileSaver.js/blob/master/FileSaver.js */
 
-export var saveAs = 'saveAs' in window ? window.saveAs : (function(view) {
+export var saveAs = saveAs || (function(view) {
 	"use strict";
 	// IE <10 is explicitly unsupported
 	if (typeof view === "undefined" || typeof navigator !== "undefined" && /MSIE [1-9]\./.test(navigator.userAgent)) {