Updated eslint ecma version to 2020

- It's time, we want to be able to use more modern features, and now we're on node 14 min this makes sense
- @TODO: do this in eslint-plugin-ghost and add new rules to guard the new features

.eslintrc.js

@@ -5,6 +5,9 @@ module.exports = {
         es6: true,
         node: true
     },
+    parserOptions: {
+        ecmaVersion: 2020
+    },
     plugins: ['ghost'],
     extends: [
         'plugin:ghost/node'