chore(package): update nyc to version 13.3.0

Closes #35

Author: greenkeeper[bot]

package.json

@@ -53,7 +53,7 @@
     "ava": "^0.25.0",
     "concurrently": "^3.6.0",
     "cz-conventional-changelog": "^2.1.0",
-    "nyc": "^12.0.2",
+    "nyc": "^13.3.0",
     "prettier": "^1.13.5",
     "semantic-release": "^15.6.0",
     "travis-deploy-once": "^5.0.0",