Add unit test code coverage requirements

[JPercival]

• Add jacoco to the maven build
• Integrate code cov with github actions

[github-actions[bot]]

Formatting check succeeded!

[codecov[bot]]

Welcome to Codecov :tada:

Once merged to your default branch, Codecov will compare your coverage reports and display the results in this comment.

Thanks for integrating Codecov - We've got you covered :open_umbrella:

[JPercival]

Did some testing with this on #380. Seems to work!