chore(package): update commitizen to version 2.9.2

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -64,7 +64,7 @@
     "babel-preset-es2015": "6.16.0",
     "babel-preset-stage-2": "6.18.0",
     "chai": "^3.4.1",
-    "commitizen": "^2.8.2",
+    "commitizen": "^2.9.2",
     "coveralls": "^2.11.6",
     "cz-conventional-changelog": "1.2.0",
     "del": "^2.2.0",