Needs update to show usage of aws-sdk v3

This sample is linked from the [AWS documentation](https://docs.aws.amazon.com/xray/latest/devguide/xray-sdk-nodejs-awssdkclients.html) so it should be updated to demonstrate the usage of the new version of the SDK (`@aaws-sdk/client-s3` etc.)

If I have understood the documentation correctly, the only change is to upgrade the `aws-sdk` to v3 using the new client packages, wrap clients with `captureAWSClient` and remove the following line:

```javascript
const AWS = AWSXRay.captureAWS(require('aws-sdk'));
```