undefined proxyprotocol.Config

[Conor-Burns]

Is this setup.go compileable with go 1.12?

go get github.com/mahrud/caddy-altonions

# github.com/mahrud/caddy-altonions
../../../mahrud/caddy-altonions/setup.go:32:21: undefined: "github.com/mastercactapus/caddy-proxyprotocol".Config
../../../mahrud/caddy-altonions/setup.go:38:19: undefined: "github.com/mastercactapus/caddy-proxyprotocol".Config
../../../mahrud/caddy-altonions/setup.go:133:19: undefined: "github.com/mastercactapus/caddy-proxyprotocol".Configs