fixed mixup of atob / btoa

index.js

@@ -2,7 +2,7 @@
   "use strict";
 
   function atob(str) {
-    return new Buffer(str, 'utf8').toString('base64');
+    return new Buffer(str, 'base64').toString('utf8');
   }
 
   module.exports = atob;

test.js

@@ -2,11 +2,12 @@
   "use strict";
 
   var atob = require('./index')
-    , expected = "SGVsbG8gV29ybGQ="
+    , encoded = "SGVsbG8gV29ybGQ="
+    , unencoded = "Hello World"
     , result
     ;
 
-  if (expected !== atob("Hello World")) {
+  if (unencoded !== atob(encoded)) {
     return;
   }