Requirements for Contributing to this repository

• Fill out the template below. Any pull request that does not include enough information to be reviewed in a timely manner may be closed at the maintainers' discretion.
• The pull request must only fix one issue at the time.
• The pull request must update the test suite to demonstrate the changed functionality.
• After you create the pull request, all status checks must be pass before a maintainer reviews your contribution. For more details, please see CONTRIBUTING.

What does this PR do?

Adds automatic test optimization tracer configuration for Ruby projects.

Description of the Change

The change is done similarly to #400

• Adds RubyConfiguration class that checks versions for ruby, gem, bundle tools available in the workspace. Afterwards it executes bundle config set frozen false to unfreeze the dependencies (required to add a new dependency, tracer in this case). Then bundle add datadog-ci command is executed to add the latest version of test optimization library. The configurator returns RUBYOPT environment variable with -rbundler/setup -rdatadog/ci/auto_instrument - this will tell Ruby VM to load Datadog's code before running tests.
• Adds RUBY to TracerLanguage enum
• Adds Ruby to README and to help-languages.html page

Alternate Designs

N/A

Possible Drawbacks

N/A

Verification Process

Verified using docker compose setup for manual testing

Step 1: start jenkins on docker compose
Step 2: run test-pipeline-ruby without test optimization

Step 3: configure Test Optimization for test-pipeline-ruby

Step 4: run test-pipeline-ruby with Datadog plugin and auto innjection

Step 5: validate that tests are present in Datadog

Additional Notes

N/A

Release Notes

N/A

Review checklist (to be filled by reviewers)

• Feature or bug fix MUST have appropriate tests (unit, integration, etc...)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have one changelog/ label attached. If applicable it should have the backward-incompatible label attached.
• PR should not have do-not-merge/ label attached.
• If Applicable, issue must have kind/ and severity/ labels attached at least.