language: objective-c
osx_image: xcode8.3
env:
  - MODE=OSX CFG=Debug
  - MODE=OSX CFG=Release
  - MODE=iOS CFG=Debug
  - MODE=iOS CFG=Release
  - MODE=tvOS CFG=Debug
  - MODE=tvOS CFG=Release
  - MODE=watchOS CFG=Debug
  - MODE=watchOS CFG=Release
script:
  - ./.travis.sh "${MODE}" "${CFG}"
notifications:
  email: false

language: objective-c
osx_image: xcode9.3
env:
  - MODE=OSX CFG=Debug
  - MODE=OSX CFG=Release
  - MODE=iOS CFG=Debug
  - MODE=iOS CFG=Release
  - MODE=tvOS CFG=Debug
  - MODE=tvOS CFG=Release
  - MODE=watchOS CFG=Debug
  - MODE=watchOS CFG=Release
script:
  - ./.travis.sh "${MODE}" "${CFG}"
notifications:
  email: false

Move to Xcode 9.3 which also means a High Sierra image.
Move to Xcode 9.3 which also means a High Sierra image.

Given the current level of flake/failure on travis, this likely will be
just as bad or worse. But moving forward for the newer compile warnings
and errors seems like a good thing.
