code: func (h Osxkeychain) Delete(serverURL string) error {
  	s, err := splitServer(serverURL)
  	if err != nil {
  		return err
  	}
  	defer freeServer(s)
  
  	errMsg := C.keychain_delete(s)
  	if errMsg != nil {
  		defer C.free(unsafe.Pointer(errMsg))
  		return errors.New(C.GoString(errMsg))
  	}
  
  	return nil
  }
docs: // Delete removes credentials from the keychain.