Return the list of commands to run.

def commands(config, names):
    """Return the list of commands to run."""
    commands = {cmd: Command(**dict((minus_to_underscore(k), v)
                                    for k, v in config.items(cmd)))
                for cmd in config.sections()
                if cmd != 'packages'}
    try:
        return tuple(commands[x] for x in names)
    except KeyError as e:
        raise RuntimeError(
            'Section [commands] in the config file does not contain the '
            'key {.args[0]!r} you requested to execute.'.format(e))