Merge pull request #235 from finscn/patch-3

fix: check for `module` object before accessing it (avoids "module is not defined" in certain environments)

src/Tween.js

@@ -859,7 +859,7 @@ TWEEN.Interpolation = {
 			return TWEEN;
 		});
 
-	} else if (typeof exports === 'object') {
+	} else if (typeof module !== 'undefined' && typeof exports === 'object') {
 
 		// Node.js
 		module.exports = TWEEN;