build(package.json): bump posthtml to v0.11.3

Author: Scrum

package.json

@@ -11,7 +11,7 @@
     "jscs": "^1.13.1",
     "jshint": "^2.8.0",
     "mocha": "^2.2.5",
-    "posthtml": "^0.8.1"
+    "posthtml": "^0.11.3"
   },
   "scripts": {
     "test": "npm run lint && mocha",