Coverallsapp Github Action Versions Save

What's Changed

• Set default values as strings per GH Action requirements by @littleforest in https://github.com/coverallsapp/github-action/pull/204
• Allow pinning of coverage reporter version by @littleforest in https://github.com/coverallsapp/github-action/pull/208

New Contributors

• @littleforest made their first contribution in https://github.com/coverallsapp/github-action/pull/204

Full Changelog: https://github.com/coverallsapp/github-action/compare/v2.2.3...v2.3.0