Write the default config file.

def write_default_config(self, filename):
        """Write the default config file.
        """
        try:
            with open(filename, 'wt') as file:
                file.write(DEFAULT_CONFIG)
            return True
        except (IOError, OSError) as e:
            print('Error writing %s: %s' % (filename, e.strerror or e), file=sys.stderr)
            return False