Update test fixtures file names to @babel/helper-plugin-test-runner naming conventions

[sthzg]

The beta versions of @babel/helper-plugin-test-runner specified the file names for automatic assertion to actual.js and expected.js, see README of beta version.

In the stable release this seems to have been changed to input.js and output.js, so that the current test suite seems to produce false positives (and not performing the actual assertions against expected.js).

[gajus]

🎉 This issue has been resolved in version 3.4.4 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀