Set project root path.

def set_root_path(self, root_path):
        """Set project root path."""
        if self.name is None:
            self.name = osp.basename(root_path)
        self.root_path = to_text_string(root_path)
        config_path = self.__get_project_config_path()
        if osp.exists(config_path):
            self.load()
        else:
            if not osp.isdir(self.root_path):
                os.mkdir(self.root_path)
            self.save()