Bump node-gyp from 3.8.0 to 4.0.0 (#177)

Bumps [node-gyp](https://github.com/nodejs/node-gyp) from 3.8.0 to 4.0.0.
- [Release notes](https://github.com/nodejs/node-gyp/releases)
- [Changelog](https://github.com/nodejs/node-gyp/blob/master/CHANGELOG.md)
- [Commits](https://github.com/nodejs/node-gyp/commits)

Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -48,7 +48,7 @@
     "mocha": "^6.1.4",
     "node-abi": "^2.7.0",
     "node-cpplint": "~0.4.0",
-    "node-gyp": "^3.8.0",
+    "node-gyp": "^4.0.0",
     "prebuild": "^8.2.1"
   },
   "dependencies": {