Use airbnb preset defaults for eslint-plugin-babel overrides

[edmorley]

The @neutrinojs/airbnb and @neutrinojs/airbnb-base presets both enable some of eslint-plugin-babel's custom rules, and switch off the corresponding default rule.

However when they enable the replacement babel/* rule, it's done with hardcoded rule options that match the eslint defaults, which in some cases doesn't match when the airbnb guide was using.

Instead, I think we should be transferring the airbnb settings across, using something like so:

const { rules: airbnbBaseStyleRules } = require('eslint-config-airbnb-base/rules/style');

  // ...
      rules: {
        'new-cap': 'off',
        'babel/new-cap': airbnbBaseStyleRules['new-cap'],

[edmorley]

The same also applies to @neutrinojs/standardjs.
I'll open a PR to fix all three.