code: func DefaultConfig() *SigningProfile {
  	d := helpers.OneYear
  	return &SigningProfile{
  		Usage:        []string{"signing", "key encipherment", "server auth", "client auth"},
  		Expiry:       d,
  		ExpiryString: "8760h",
  	}
  }
docs: // DefaultConfig returns a default configuration specifying basic key
  // usage and a 1 year expiration time. The key usages chosen are
  // signing, key encipherment, client auth and server auth.