This code is not designed well: https://github.com/gorilla/handlers/blob/master/recovery.go#L49

func RecoveryLogger(logger *log.Logger) RecoveryOption {
	return func(h http.Handler) {
		r := h.(*recoveryHandler)
		r.logger = logger
	}
}

You should avoid accepting structs and instead try to accept interfaces whenever possible. In this particular case, since you are only using the Println(...interface{}) method, you should create an interface for the input argument like this:

type Logger interface {
    Println(v ...interface{}}
}

This would allow users to pass a custom structured logger (e.g. Logrus), which might have some other fields/tags like environment, host, user, application etc. Unstructured logs in a highly distributed environment are totally useless.