Synchronize CI configuration from `homebrew/cask`. #314

Annotations

4 errors and 7 warnings

Canceling since a higher priority waiting request for 'refs/pull/53/merge' exists

1 problem in 1 cask detected.

The homepage URL http://www.rmartijnr.eu/iconvert.html is not reachable

Process completed with exit code 1.

No checksum defined for cask 'iconvert', skipping verification.

iconvert has been deprecated because it is discontinued upstream!

No checksum defined for cask 'iconvert', skipping verification.

macOS's Gatekeeper has been disabled for this Cask