chore(package): update commitizen to version 3.0.6

Closes #35

Author: greenkeeper[bot]

package.json

@@ -62,7 +62,7 @@
     "babel-preset-es2015": "^6.16.0",
     "babel-preset-stage-2": "^6.22.0",
     "babel-register": "^6.16.3",
-    "commitizen": "^2.8.6",
+    "commitizen": "^3.0.6",
     "conventional-changelog-cli": "^1.2.0",
     "coveralls": "^2.11.14",
     "cz-conventional-changelog": "^1.2.0",