Merge pull request #850 from weslly/grunt

Update grunt dependencies and node.js version

package.json

@@ -15,15 +15,15 @@
     "url": "http://opensource.org/licenses/MIT"
   }],
   "engines": {
-    "node": ">= 0.8.0"
+    "node": ">= 0.10.0"
   },
   "devDependencies": {
-    "grunt": "~0.4.0",
+    "grunt": "~0.4.1",
     "grunt-contrib-clean": "~0.5.0",
-    "grunt-contrib-jshint": "~0.1.1",
-    "grunt-contrib-uglify": "~0.1.1",
-    "grunt-contrib-watch": "~0.2.0",
-    "grunt-recess": "~0.3.0",
+    "grunt-contrib-jshint": "~0.6.3",
+    "grunt-contrib-uglify": "~0.2.2",
+    "grunt-contrib-watch": "~0.5.2",
+    "grunt-recess": "~0.3.5",
     "grunt-imageoptim": "~1.2.11"
   }
 }