When one parameter contains blank, it should be wrapped with ".

[memorylorry]

Hope to let argparse to interpreter dict type

1. I define test_config.yml file as following:

CMD: "python train.py"

HPARAMS:
   lr: [0.01, 0.02]
   momentum: 0.5
   dataset:
     name: 'aerial'
     class: 'dataset.AerialDataset'
     root-dir: '/home/cv/dataset/aerial'
     train:
       dir: 'train'
       batch_size: 10

2. I execute python -m runx.runx test_config.yml -i -n, then command line prints:

python train.py --lr 0.01 --momentum 0.5 --dataset {'name': 'aerial', 'class': 'dataset.AerialDataset', 'root-dir': '/home/cv/dataset/aerial', 'train': {'dir': 'train', 'batch_size': 10}}
python train.py --lr 0.02 --momentum 0.5 --dataset {'name': 'aerial', 'class': 'dataset.AerialDataset', 'root-dir': '/home/cv/dataset/aerial', 'train': {'dir': 'train', 'batch_size': 10}}

You can notice that parameter dataset is a dict type, but it can't be interpreterd by argparse module with eval type. This is because dataset parameter is truncated into {'name':, this style cannot be interpreter by eval function.

3. So I try to transform dict into str. And set eval type of argparse arguments, this would solve this problem. But it need runx composite dict paramter wapped with ". Therefore, I add this feature in this commit.