Fixes #1212 - Ignore flatpickr file in vendor if auto import is enabled

[ahamed-althaf]

#1212

Example:

ember-cli-build.js

'use strict';

const EmberAddon = require('ember-cli/lib/broccoli/ember-addon');

module.exports = function (defaults) {

  let app = new EmberAddon(defaults, options);

  /*
    This build file specifies the options for the dummy test app of this
    addon, located in `/tests/dummy`
    This build file does *not* influence how the addon or the app using it
    behave. You most likely want to be modifying `./index.js` or app's build file
  */

  flatpickr: {
    includeInVendor: false // true or false should decide whether it needs to be included in vendor file or not.
  }
};

In a specific route file where we need to use flatpickr

import Route from '@ember/routing/route';

export default Route.extend({
  model() {
    return import('flatpickr').then((module) => module.default);
  }
});