chore(package): update nyc to version 14.1.0

Closes #6

Author: greenkeeper[bot]

package.json

@@ -31,7 +31,7 @@
     "bindings": "~1.3.0",
     "mocha": "^5.0.0",
     "nan": "^2.8.0",
-    "nyc": "^12.0.1",
+    "nyc": "^14.1.0",
     "ref-array": "^1.2.0",
     "ref-napi": "^1.4.0"
   }