Added 'name' as a transport option

#### What's this PR do?
This would allow for winston to log to different databases.

example:
```
var logger = new (winston.Logger) ({
  transports: [
    new winston.transports.MongoDB({name: 'mongodb-info', dbUri: uri_1}),
    new winston.transports.MongoDB({name: 'mongodb-error', dbUri: uri_2})
  ]
});
```

#### What are the relevant tickets?
#40