I keep getting "use 'esversion: 6'" errors - how to make it stop?

So I have the latest version of NPM (5.5.1) and keep getting ES6 warnings. Example - using "const" [jshint] 'const' is available in ES6 (use 'esversion: 6') or Mozilla JS extensions (use moz). (W104) Isn't ES6 standard now?

Submitted December 13, 2017 at 02:24PM by HuckleberryC