chore(package): update cz-conventional-changelog to version 3.1.0

Closes #28

Author: greenkeeper[bot]

package.json

@@ -65,7 +65,7 @@
     "commitizen": "^2.8.6",
     "conventional-changelog-cli": "^1.2.0",
     "coveralls": "^2.11.14",
-    "cz-conventional-changelog": "^1.2.0",
+    "cz-conventional-changelog": "^3.1.0",
     "eslint": "^3.14.0",
     "eslint-plugin-ava": "^4.0.1",
     "fake-indexeddb": "^1.0.8",