feat: bump yargs from 15.4.1 to 16.2.0 (#175)

Bumps [yargs](https://github.com/yargs/yargs) from 15.4.1 to 16.2.0.
- [Release notes](https://github.com/yargs/yargs/releases)
- [Changelog](https://github.com/yargs/yargs/blob/master/CHANGELOG.md)
- [Commits](yargs/yargs@v15.4.1...v16.2.0)

Node 8 is no longer supported in this version

package.json

@@ -59,6 +59,6 @@
     "through2-concurrent": "^2",
     "vinyl": "^2.2.0",
     "vinyl-fs": "^3",
-    "yargs": "^15"
+    "yargs": "^16"
   }
 }