Add `cli-plugin-unit-ava`

What problem does this feature solve?

AVA test runner.

Add unit-ava in addition to the existing unit-mocha and unit-jest core plugins. unit-ava would be exposed in the same way as jest and mocha support and given as an option for unit testing configuration.

What does the proposed API look like?

The API / implementation would follow the pattern(s) established by unit-jest and unit-mocha.

[LinusBorg]

How is the testing story with .vue files with ava these days?

/ping @eddyerburgh tested ava some time ago and performance of existing solutions to transpile .vue files in ava were disappointing, to say the least.

Generelly I don’t think we want to add every testing framework as a core pluin, just like we won’t add every preprocessor and every compile-to-js language to it (no coffeescript! 😛)

So in order for a PR to be accepted, this proposition would have to:

1. Provide a great testing experience with Vue, especially .vue files
2. Gather enough support from the community to make clear using ava with Vue has enough support to add it as a core plugin.

If that doesn’t happen, you can ofg course make it a “normal” plugin to the cli, which means users would simpl have to do this to add ava after the initial vue create setup:

npm i -D vue-cli-plugin-ava
vue invoke ava

[dnlup]

I am developing a plugin, if anyone would like to try it and give me some feedback here is the repo: https://github.com/dnlup/vue-cli-plugin-unit-ava