Fix 'no-shared-component-data' false positive when using arrow functions

[armano2]

fixes #154

[mysticatea]

I suspect that this test case is not correct.
The filename is .vue and the code is in outside of <script> element.

[michalsnik]

This is sort of correct @mysticatea I think. This plugin doesn't transform <script></script> from a vue file. It's part of eslint-vue-parser responsibilities so here we expect that any code inside script tag will be accessible as usual. That's why we write this code directly without extra script tag. All we need to know in our rules is the extension of the file to detect if simple export default should be treated as component.

[mysticatea]

Ah, I was under the impression that parserOptions has parser: "vue-eslint-parser". I'm sorry.