chore(package): update commitizen to version 3.0.2

Closes #37

Author: greenkeeper[bot]

package.json

@@ -41,7 +41,7 @@
     "@types/common-tags": "^1.2.5",
     "@types/jest": "^21.1.2",
     "@types/node": "^8.0.6",
-    "commitizen": "^2.9.6",
+    "commitizen": "^3.0.2",
     "cz-conventional-changelog": "^2.0.0",
     "danger": "^1.0.0",
     "gh-pages": "^1.0.0",