fix async dep

package.json

@@ -71,7 +71,8 @@
     "brfs": "=1.0.0",
     "chai": "=1.9.1",
     "uglifyify": "=1.2.3",
-    "extend": "~1.2.1"
+    "extend": "~1.2.1",
+    "async": "~0.2.10"
   },
   "devDependencies": {
     "grunt-contrib-watch": "~0.5.3",
@@ -81,7 +82,6 @@
     "grunt-markdown": "~0.5.0",
     "mocha": ">=1.15.1",
     "brfs": "~1.0.0",
-    "async": "~0.2.10",
     "commander": "~2.1.0",
     "browser-pack": "~2.0.1",
     "istanbul": "~0.2.6"