Added support for "create log folder" if it doesn't exist

Added support for "create log folder" if it doesn't exist

Default behaviour is not changed - i.e. it won't create log folder by default, but if you pass in `createLogFolder: true`, then it will create a folder if it does not exist.

Added a very minimal test to verify log folder creation works.

Below is a simple code snippet. All that's new is the line with `createLogFolder: true` 
```
	// Create the logger
	var log = new (winston.Logger)({
		transports: [
			new (winston.transports.FileRotateDate)( {
				filename: logFile,
				dirname: logDir,
				json: false,
				maxsize: 10,
				createLogFolder: true
			})
		],
	});
```