Chef18 compliant

• Update CHANGELOG

• Fix tests (#3)

  • Executor chef in sous-chefs is using older Ubuntu release

  • Use Chef Workstation, not ChefDK

  • Use CircleCI-recommended image

• Fix ValidationFailed error (#4)

  • converts to strings

  • Add test

• Fix ChefCorrectness/OctalModeAsString (#5)

• Resource unified_mode for Chef 18 (#6)

• Rename branch to main (#7)

• Bump up version (#8)