v4.0.0-0 Prerelease

Added

• automatically wrap and indent help descriptions for options and commands (#1051)
• .exitOverride() allows override of calls to process.exit for additional error handling and to keep program running (#1040)
• dev: work in progress GitHub Actions support (#1027)

Changed

• dev: switch tests from Sinon+Should to Jest with major rewrite of tests (#1035)
• call default subcommand even when there are unknown options (#1047)
• Breaking Commander is only officially supported on Node 8 and above (#1053)

Fixed

• Breaking keep command object out of program.args when action handler called (#1048)
  • also, action handler now passed array of unknown arguments
• complain about unknown options when program argument supplied and action handler (#1049)
  • this changes parameters to command:* event to include unknown arguments
• removed deprecated customFds option from call to child_process.spawn (#1052)