chore(ci): persist unit test output

[thisislawatts]

Pull Request Submission

Please check the boxes once done.

The pull request must:

• Reviewer Documentation
  • follow CONTRIBUTING rules
  • be accompanied by a detailed description of the changes
  • contain a risk assessment of the change (Low | Medium | High) with regards to breaking existing functionality. A change e.g. of an underlying language plugin can completely break the functionality for that language, but appearing as only a version change in the dependencies.
  • highlight breaking API if applicable
  • contain a link to the automatic tests that cover the updated functionality.
  • contain testing instructions in case that the reviewer wants to manual verify as well, to add to the manual testing done by the author.
  • link to the link to the PR for the User-facing documentation
• User facing Documentation
  • update any relevant documentation in gitbook by submitting a gitbook PR, and including the PR link here
  • ensure that the message of the final single commit is descriptive and prefixed with either feat: or fix: , others might be used in rare occasions as well, if there is no need to document the changes in the release notes. The changes or fixes should be described in detail in the commit message for the changelog & release notes.
• Testing
  • Changes, removals and additions to functionality must be covered by acceptance / integration tests or smoke tests - either already existing ones, or new ones, created by the author of the PR.

What does this PR do?

Introduce junit reporter for unit tests and upload to CircleCI to use with their Test Insights feature.

The aim being to track performance of our tests to understand:

• Slow tests
• Identify flakes

Where should the reviewer start?

Example upload of results:
https://app.circleci.com/pipelines/github/snyk/cli/20964/workflows/43f2f73b-4a12-4c67-a09e-ea58419fca9f/jobs/312279/tests