Does not work with non-class decorator Vue

[renestalder]

As opposed to #19, it does not work with non-class decorator components.

The fixture is not using the correct way of one should write components with TypeScript, thus the tests will probably be successful.

Current fixture:

<template>
  <div>{{ foo }}</div>
</template>

<script lang="ts">
export default {
  data () {
    return {
      foo: 'Hello'
    }
  }
}
</script>

<style>
div {
  color: red;
}
</style>

The correct fixture would be:

<template>
  <div>{{ foo }}</div>
</template>

<script lang="ts">
import Vue from 'vue';
export default Vue.extend({
  data () {
    return {
      foo: 'Hello'
    }
  }
});
</script>

<style>
div {
  color: red;
}
</style>

With this, vuetype throws an error:

Default export of the module has or is using private name 'VueConstructor'.

[trusktr]

Regarding the all-too-common "has or is using private name" error, I've opened a request to fix issues like these in TypeScript by bringing declaration files to parity with language features. microsoft/TypeScript#35822