Migrate CI from Travis to GitHub Actions

[mishina2228]

Since June 15th, 2021, the building on travis-ci.org is ceased. This PR migrates CI from Travis CI to GitHub Actions. Here are the details:

• Add Ruby 2.7, 3.0, 3.1 and head to the CI matrix
• Remove and ignore Gemfile.lock
  • Existence of Gemfile.lock prevents testing on multiple Ruby versions.

• Update RubyGems to the latest

  • Using old RubyGems, the following warning is displayed and the CI fails.

    1) Foreman::CLI run can run a command
    Failure/Error: expect(forked_foreman("run echo 1")).to eq("1\n")
    
    expected: "1\n"
        got: "Your RubyGems version (2.7.6.3) has a bug that prevents `required_ruby_version` from working for Bun...yGems to avoid future breakage and silence this warning by running `gem update --system 3.2.3`\n1\n"

• Use the latest fakefs
  • fakefs v0.10.x does not work with the latest Ruby.
• Replace File.exists? at spec/foreman_spec.rb with File.exist?
  • File.exists? is being removed in Ruby 3.2.
  • In this PR, only File.exists? in spec/foreman_spec.rb is replaced.
• Pass a block instead of a lambda to Rspec's expect to suppress the following deprecation warning

  The implicit block expectation syntax is deprecated, you should pass a block rather than an argument to `expect` to use the provided block expectation matcher or the matcher must implement `supports_value_expectations?`. e.g  `expect { value }.to raise SystemExit` not `expect(value).to raise SystemExit`

• Add GitHub token permissions for workflow
  • GitHub asks developers to define workflow permissions, see below for securing GitHub workflows against supply-chain attacks.
  • https://github.blog/changelog/2021-04-20-github-actions-control-permissions-for-github_token/
  • https://docs.github.com/en/actions/security-guides/automatic-token-authentication#modifying-the-permissions-for-the-github_token

codeclimate-test-reporter has been deprecated and the following message displayed:

  Code Climate's codeclimate-test-reporter gem has been deprecated in favor of
  our language-agnostic unified test reporter. The new test reporter is faster,
  distributed as a static binary so dependency conflicts never occur, and
  supports parallelized CI builds & multi-language CI configurations.

  Please visit https://docs.codeclimate.com/v1.0/docs/configuring-test-coverage
  for help setting up your CI process with our new test reporter.

I wanted to deal with this, but since I don't have the token of CodeClimate, I passed on it.

[daande]

@mishina2228 Any ETA on this being released?

[mishina2228]

@daande I feel the same way, but I don't have a privilege to merge This PR.

@ddollar Hi, I would appreciate it if you review this PR, thanks!

[ddollar]

Thanks @mishina2228 ! Sorry this took so long to get merged.

[knu]

@ddollar Isn't this worth a new gem release? 🙏

[Geesu]

Can we get a new gem release?

[mishina2228]

This PR only changes the code related to CI, not the production code. And I now realize that the explanation of the File.exists? replacement is insufficient. I have updated the description.

I would be happy to see #788 merged in which File.exists? is completely renamed.