Elastic Beanstalk migration Upload Source Code to S3 instructions

Hi there!

I recently attempted this lab at an AWS hosted event, and noticed that there is no IAM role that ever gets attached to the Webserver instance. This breaks the step in **upload-source-code-to-s3.en.md**, as the EC2 doesn't have the permissions required to upload the .zip bundle to Beanstalk. For the AWS hosted event there is a workaround using another instance profile role available that has S3 PutObject permissions. However, not sure if there should be an explicit callout to use that role, or to create a new one with S3 permissions.