using incomplete runners by default seems a bit confusing

[christopherhesse]

The default behavior is to use images that behave quite differently from the github versions: https://github.com/nektos/act#default-runners-are-intentionally-incomplete

This seems odd to me because the selling point was to run my github actions locally, but they fail because the image is different. The documentation even says "The environment variables and filesystem are all configured to match what GitHub provides."

Given that, it seems like node:12.6-buster-slim should be the opt-in image rather than the nektos/act-environments-ubuntu:18.04 one. The nektos/act-environments-ubuntu:18.04 image is like 20GB, but hard drives are pretty large these days.

What do you guys think?

[cplee]

While I agree, I just thought it would be a tough sell to ask folks to download a 20GB docker image before they could start using the tool. Let's move this discussion to #107.