Updated the CI test workflow for v8 and Laravel 10

[danielmorell]

Description of the change

This PR makes it so that our tests will run for the master branch. This is for the upcoming v8.x and above. Tests for the previous version v7.x of our Laravel package have been moved to the ci-7.x.yml file in #144.

To make the tests run we need to temporarily include the following lines in the install step.

composer config minimum-stability dev
composer config prefer-stable true

Once we release stable v4.0.0 of the core rollbar/rollbar library, we can remove these two lines.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Maintenance
• New release

Related issues

None

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

Code review

• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• "Ready for review" label attached to the PR and reviewers assigned
• Issue from task tracker has a link to this pull request
• Changes have been reviewed by at least one other engineer