Replace Travis CI with GitHub Actions

[devin-ai-integration]

This PR replaces Travis CI with GitHub Actions for CI/CD.

• Removed Travis CI configuration and dependencies
• Added GitHub Actions workflow to run tests on Ruby versions 2.7.8, 3.0.7, 3.1.6, 3.2.7, 3.3.7, 3.4.2, and 3.5-dev
• Updated Coveralls configuration for GitHub Actions

Link to Devin run: https://app.devin.ai/sessions/bd482b3ae98040198b0f38a478dc7548

[devin-ai-integration]

🤖 Devin AI Engineer

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• Address comments on this PR. Add "(aside)" to your comment to have me ignore it.
• Look at CI failures and help fix them

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⚙️ Control Options:

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[Copilot]

PR Overview

This PR replaces Travis CI with GitHub Actions for CI/CD. The changes include adding a GitHub Actions workflow, updating Coveralls configuration, and removing Travis CI-related dependencies.

• Added a new GitHub Actions workflow file (.github/workflows/ci.yml) to run tests on various Ruby versions
• Updated Coveralls configuration (.coveralls.yml) to reflect GitHub Actions as the CI service
• Removed Travis CI gems from the Gemfile and eliminated related setup in spec/spec_helper.rb

Reviewed Changes

File	Description
.github/workflows/ci.yml	New workflow configuration for GitHub Actions with Ruby versions matrix
.coveralls.yml	Updated service name from travis-ci to github-actions
Gemfile	Removed Travis CI gems
spec/spec_helper.rb	Removed Coveralls initialization to align with the new CI setup

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

[Copilot]

The Ruby version 'head' is used, but the PR description specifies '3.5-dev'. Please update to match the documented Ruby version.

Suggested change

	- 'head'
	- '3.5-dev'