add ci and general update/refactor

[cpanato]

The code refactor was to get rid of the lint complaint:

main.go:37:5: exitAfterDefer: log.Fatalf will exit, and `defer os.RemoveAll(tmp)` will not run (gocritic)
                                log.Fatalf("could not clone repo: %s %s", err, string(out))
                                ^

in a nice way, but if you dont like it i can revert