Skopeo fetcher

[giuseppe]

add the command layers to skopeo. Code copied from cifetch.

[runcom]

Things left to do there:

• sync with upstream docker code (since there's some change in vendor/ here) - I'll do it asap
• add smoke tests under integration/ for the layer command - @giuseppe?
• add smoke tests under integration/ for the inspect command
• update README for the layer command

Current tests pass, thanks @giuseppe - current code is fine right now but it will undergo an heavy refactor to externalize registries' interactions (/cc @vbatts)

[giuseppe]

runcom, I resync the file in vendor/ from github.com/docker/docker/pkg/homedir/homedir.go

[runcom]

runcom, I resync the file in vendor/ from github.com/docker/docker/pkg/homedir/homedir.go

this has to be done with godep ensuring all deps are fine and in sync

[giuseppe]

ok thanks, just I hit this issue when I use godep:

# github.com/docker/docker/cliconfig
../../docker/docker/cliconfig/config.go:104: authConfig.Email undefined (type types.AuthConfig has no field or method Email)
# github.com/docker/docker/image/v1
../../docker/docker/image/v1/imagev1.go:34: v1Image.ContainerConfig.Cmd.Slice undefined (type strslice.StrSlice has no field or method Slice)
godep: exit status 2

[runcom]

wait wait, I did a huge mistake, sorry, the script to vendor deps is in ./hack/vendor.sh sorry about this 😢

[giuseppe]

fixed in the version here ⬆️

[rhatdan]

I would like to change default skopeo imediately to use the inspect command so that we don't release skopeo into a supported release using the current CLI. Then you can continue to work on this enhancement to skopeo in time.

[runcom]

@rhatdan I'll fix and merge this on top of what @giuseppe did hopefully today or tomorrow