Inconsistent script database name in Quick Start causes docker-compose service startup to fail

【Scenes】
According to the quick start document, use the docker-compose command to start the service, but the database authentication fails

【Reason】
[db.js](https://github.com/apache/servicecomb-kie/blob/master/deployments/db.js)，

- mongodb init database name is servicecomb
- db.js init database name is kie

```
{
user: "kie",
pwd: "123",
roles:[
{
role: "readWrite",
db: "kie"
}
]
}
```

[Error Log]
can not dial db:server returned error on SASL authentication step: Authentication failed