chore(package): update nyc to version 13.3.0

Closes #12

Author: greenkeeper[bot]

package.json

@@ -64,7 +64,7 @@
     "eslint": "^3.7.1",
     "eslint-plugin-ava": "^4.0.0",
     "husky": "^0.12.0",
-    "nyc": "^10.0.0",
+    "nyc": "^13.3.0",
     "rimraf": "^2.5.4",
     "validate-commit-msg": "^2.8.2"
   },