Plan to drop support for macOS 10.13 and older

[sindresorhus]

We plan to drop support for macOS 10.13 and older on the 1st of November 2020. At that date, we'll do a special release for 10.13 without the updater, so 10.13 users can continue to use that version without problems. We'll also update the readme/website to include a link to the last compatible version for 10.13.

Why are we doing this? None of us use 10.13 and it's becoming a burden to support it because Swift-based command-line only support macOS 10.14.4 and later by default, and we use many in Kap for various functionality.

[sindresorhus]

We can now do this.

[realimpat]

I just tried to install kap via brew cask on macOs 10.14.6, and the application would not launch -- Kap showed as a running process but no gui or menubar appeared. I am not sure if this is related. just FYI.