Fix for Dynamic imports not present

[segundaestrella]

What problem does this feature solve?

The fix #864 for dynamic imports seems lost.

On the repo changelog is listed in the release 1.0.0-beta.22 (2018-07-29)
https://github.com/vuejs/vue-test-utils/blob/dev/CHANGELOG.md

On the vue-test-utils package changelog is not listed
https://github.com/vuejs/vue-test-utils/blob/dev/packages/test-utils/CHANGELOG.md

And with the latest release a test with dynamic import still fails

      [Vue warn]: Failed to resolve async component: function vsMobileCalendarOverview() {
        return import('./MobileCalendarOverview.vue');
      }
      Reason: Error: Not supported
    console.error node_modules/vue/dist/vue.runtime.common.js:589
      [Vue warn]: Failed to resolve async component: function vsMobileCalendarDaily() {
        return import('./MobileCalendarDaily.vue');
      }
      Reason: Error: Not supported

What does the proposed API look like?

I don't understand what is going on:)

[Ic3m4n34]

Why is this closed? I have the same issue. If someone knows how to fix this, please let me know.