chore(package): update ref-napi to version 2.0.1

Closes #11

Author: greenkeeper[bot]

package.json

@@ -33,6 +33,6 @@
     "nan": "^2.8.0",
     "nyc": "^12.0.1",
     "ref-array": "^1.2.0",
-    "ref-napi": "^1.4.0"
+    "ref-napi": "^2.0.1"
   }
 }