Imports github.com/go-acme/lego/challenge/dns01 github.com/go-acme/lego/log github.com/go-acme/lego/platform/config/env github.com/go-acme/lego/platform/wait golang.org/x/net/context golang.org/x/oauth2/google google.golang.org/api/dns/v1 google.golang.org/api/googleapi Standard library imports encoding/json errors fmt io/ioutil net/http strconv time