reduce npm package size

Author: OlehDutchenko

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "node-w3c-validator",
-  "version": "1.6.0",
+  "version": "1.6.1",
   "description": "Wrapper for The Nu Html Checker (v.Nu)",
   "main": "./lib/validator.js",
   "scripts": {
@@ -13,6 +13,10 @@
   "bin": {
     "node-w3c-validator": "./bin/cmd.js"
   },
+  "files": [
+    "bin",
+    "lib"
+  ],
   "nodeW3Cvalidator": {
     "suppressErrors": [
       "Attribute “href” not allowed"