Switch to Github Actions for Ruby 2.4|5|6|7 & 3
• Switch to Github Actions for Ruby 2.4|5|6|7 & 3 • Update Rubocop and upgrade syntax with Ruby 2.7 target, but retaining backwards compatibility with Ruby back to 1.9.3 for 1.4.x releases.
• Switch to Github Actions for Ruby 2.4|5|6|7 & 3 • Update Rubocop and upgrade syntax with Ruby 2.7 target, but retaining backwards compatibility with Ruby back to 1.9.3 for 1.4.x releases.