chore(package): update nyc to version 13.3.0

Closes #16

Author: greenkeeper[bot]

package.json

@@ -44,7 +44,7 @@
     "ava": "^0.25.0",
     "coveralls": "^3.0.0",
     "eslint-config-xo-lukechilds": "^1.0.0",
-    "nyc": "^11.0.3",
+    "nyc": "^13.3.0",
     "this": "^1.0.2",
     "xo": "^0.20.1"
   }