docs: link to tyu project (#256)

tyu aims to make testing of vue components easy to **run**.

It uses `vue-test-utils` and works out of the box with apps using `babel-preset-vue-app`.

Author: atilacamurca

docs/en/guides/choosing-a-test-runner.md

@@ -43,3 +43,4 @@ Read the following guides for different setups:
 - [Example project with Mocha](https://github.com/vuejs/vue-test-utils-mocha-webpack-example)
 - [Example project with tape](https://github.com/eddyerburgh/vue-test-utils-tape-example)
 - [Example project with AVA](https://github.com/eddyerburgh/vue-test-utils-ava-example)
+- [tyu - Delightful web testing by egoist](https://github.com/egoist/tyu)