remove binding.gyp from npm package (#21)

Author: rochdev

.npmignore

@@ -6,7 +6,6 @@
 !LICENSE
 !LICENSE-3rdparty.csv
 !README.md
-!binding.gyp
 !index.d.ts
 !index.js
 !package.json

package.json

@@ -8,7 +8,6 @@
   "license": "Apache-2.0",
   "homepage": "https://github.com/DataDog/dd-native-metrics-js#readme",
   "scripts": {
-    "install": "(node scripts/should_rebuild && node-gyp-build) || exit 0",
     "rebuild": "node-gyp rebuild",
     "lint": "node scripts/check_licenses.js && eslint .",
     "test": "mocha 'test/**/*.spec.js'"