[BUG] Monitoring service logs: Make cloudwatch log group a CF output

[adamjkeller]

Problem:

When reviewing service logs using awslogs, we dynamically grab the log group and set it as an environment variable. While this is good when using in a brand new AWS account, if you have done this workshop before and run through it again, there could be multiple log groups.

Solution:

Set the log group as a CF output, and when tailing the logs, use the CF output as the log_group variable.