use prepare instead of install

Author: jairo-bc

package.json

@@ -28,7 +28,7 @@
   "gypfile": true,
   "scripts": {
     "coverage": "nyc npm run test",
-    "install": "node scripts/install.js",
+    "prepare": "node scripts/install.js",
     "postinstall": "node scripts/build.js",
     "lint": "eslint bin/node-sass lib scripts test",
     "test": "mocha test/{*,**/**}.js",