validate the trial config in pai platform

def validate_pai_trial_conifg(experiment_config):
    '''validate the trial config in pai platform'''
    if experiment_config.get('trainingServicePlatform') == 'pai':
        if experiment_config.get('trial').get('shmMB') and \
        experiment_config['trial']['shmMB'] > experiment_config['trial']['memoryMB']:
            print_error('shmMB should be no more than memoryMB!')
            exit(1)