Imports github.com/urfave/cli github.com/xenolf/lego/providers/http/webroot github.com/xenolf/lego/providers/http/memcached github.com/xenolf/lego/providers/dns github.com/xenolf/lego/acme Standard library imports crypto/elliptic encoding/pem crypto/ecdsa bufio bytes crypto crypto/rand text/tabwriter crypto/x509 encoding/json errors fmt io/ioutil log net/http net/url os path strings time