Saving output for configured variable name.

        Args:
            shell_entry(dict): shell based configuration (shell, docker container or Python).
            output: list of strings representing output of last shell

def __handle_variable(self, shell_entry, output):
        """
        Saving output for configured variable name.

        Args:
            shell_entry(dict): shell based configuration (shell, docker container or Python).
            output: list of strings representing output of last shell
        """
        if 'variable' in shell_entry:
            variable_name = shell_entry['variable']
            self.pipeline.variables[variable_name] = "\n".join(output)