Enable caching on Appveyor


I have a package with some large dependencies that takes anywhere from 30 mins to hitting the 1h auto-cancel time limit on appveyor. It would be really nice to cache the built versions of the larger/slower dependencies on appveyor to speed testing up, and avoid the 1h limit.

Has anyone achieved caching with packages? Purely adding the package dirs to appveyor.yml doesn’t work. i.e.

  - C:\Users\appveyor\.julia\packages\Homebrew
  - C:\Users\appveyor\.julia\packages\WinRPM
  - C:\Users\appveyor\.julia\packages\Cairo
  - C:\Users\appveyor\.julia\packages\Gtk


maybe https://www.appveyor.com/docs/build-cache/ can help?