* Setup GitHub Actions
* Use macos-latest image.
Big Sur is still in preview.
* Update bundler before trying to install.
* Use `ruby/setup-ruby@v1` for setting up bundler.
* Update bundled with version and specify specific ruby-version.
* Setup separate danger job using action and setup test job matrix.
* Fix matrix variable name.
* Adjust simulators that are being used.
* Add GITHUB_TOKEN to danger job.