Parse a feature command.

def _parse_feature(self, info):
        """Parse a feature command."""
        parts = info.split(b'=', 1)
        name = parts[0]
        if len(parts) > 1:
            value = self._path(parts[1])
        else:
            value = None
        self.features[name] = value
        return commands.FeatureCommand(name, value, lineno=self.lineno)