Update the new deployment for polarDB

[NLGithubWP]

1. Add training datasets
2. Update the Dockerfile for Postgresql and add the Dockerfile for the singa with polarDB
3. Update README.md
4. Add init script for running the code once docker started

[lzjpaul]

We separate the training dataset from this commit

[lzjpaul]

1. Add training datasets

For the dataset, we use an URL to download it.

2. Update the Dockerfile for Postgresql and add the Dockerfile for the singa with polarDB
3. Update README.md
4. Add init script for running the code once docker started

[lzjpaul]

have deleted some sample data